From 70dc18e226e7d64aa0365dc46937b1ec36c28ca8 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Tue, 3 Nov 2026 21:51:41 +0000
Subject: [PATCH] Add artist Media tab, tags, Random, hash lookup and
 back-to-top arrow

- Artist profiles get a Media tab: every image, GIF and video from their
  posts in a grid, filtered All / Photos / GIFs / Videos.
- A pink arrow appears once a list is two screens down and scrolls back
  to the top (feeds, popular artists, media, tags, hash results).
- Holding an image in the viewer presses it in while the hold registers,
  then springs back, so the download button isn't the only feedback.
- Explore has a Tags tab: the site's popular tags, filtered as you type,
  and "Posts tagged #..." for any tag. A post's tag offers that artist's
  posts or every artist's.
- Hash lookup in the sidebar: paste a SHA-256 or pick a file to hash on
  the device, then list the posts that hold it.
- Random in the sidebar shows a random post or artist, with a shuffle
  button and a gear to switch; the first visit asks which.
- The sidebar scrolls on short screens.

Tag lists, tagged posts and random picks are scraped from the web pages
(the API ignores tag and has no random); see docs/pawchive-api.md.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LtGkw1AxGnokeZefgJcr1w
---
 AGENT.md                     |  41 +++++-
 docs/pawchive-api.md         |   8 +
 lib/core/api.dart            |  70 ++++++++-
 lib/core/app_state.dart      |  11 ++
 lib/core/file_hash.dart      |  24 +++
 lib/core/models.dart         |  54 +++++++
 lib/core/store.dart          |  11 ++
 lib/ui/creator_media.dart    | 273 +++++++++++++++++++++++++++++++++++
 lib/ui/creator_page.dart     |   5 +-
 lib/ui/hash_lookup_page.dart | 241 +++++++++++++++++++++++++++++++
 lib/ui/home.dart             | 188 +++++++++++++-----------
 lib/ui/media_viewer.dart     |  52 +++++--
 lib/ui/popular.dart          |  18 ++-
 lib/ui/post_page.dart        |  41 +++++-
 lib/ui/random_page.dart      | 207 ++++++++++++++++++++++++++
 lib/ui/search_page.dart      | 124 +++++++++++++++-
 lib/ui/tag_page.dart         |  71 +++++++++
 lib/ui/widgets.dart          | 162 +++++++++++++++++----
 test/back_to_top_test.dart   |  42 ++++++
 test/explore_test.dart       | 203 ++++++++++++++++++++++++++
 20 files changed, 1705 insertions(+), 141 deletions(-)
 create mode 100644 lib/core/file_hash.dart
 create mode 100644 lib/ui/creator_media.dart
 create mode 100644 lib/ui/hash_lookup_page.dart
 create mode 100644 lib/ui/random_page.dart
 create mode 100644 lib/ui/tag_page.dart
 create mode 100644 test/back_to_top_test.dart
 create mode 100644 test/explore_test.dart

diff --git a/AGENT.md b/AGENT.md
index c1dd721..aeb92ac 100644
--- a/AGENT.md
+++ b/AGENT.md
@@ -33,8 +33,9 @@ lib/
   main.dart            App root: splash -> onboarding -> home, revealed from the bottom
   core/                No widgets (except updates.dart's Flutter binding); safe for the background isolate
     config.dart        Hosts, user agent, page size
-    models.dart        Creator, Post, MediaFile, Poll, Favorite, Like, Follow + NotifyLevel, Community*, UpdateNotice, ... and JSON parsing; threadComments
-    api.dart           PawchiveApi (all HTTP); scrapers for DMs, popular posts, similar artists, community chats
+    models.dart        Creator, Post, MediaFile, Poll, Favorite, Like, Follow + NotifyLevel, Community*, UpdateNotice, PawchiveLink, HashLookup, ... and JSON parsing; threadComments
+    api.dart           PawchiveApi (all HTTP); scrapers for DMs, popular posts, tags, tagged posts, similar artists, community chats; random redirects; hash lookup
+    file_hash.dart     sha256Hex (streamed, for hash lookup) and isSha256
     store.dart         Store: SharedPreferencesAsync + secure storage (session cookie); AppSettings
     backup.dart        Backup file (follows, likes, sign-in sealed with AES-GCM + PBKDF2), mergeFollows / mergeFavorites
     feeds.dart         Feed (paged ChangeNotifier), OffsetFeed, PopularFeed, FollowingFeed (k-way merge)
@@ -47,7 +48,7 @@ lib/
   ui/
     app_scope.dart     AppScope.of(context) / AppScope.read(context) give AppState
     theme.dart         Palette (from assets), buildTheme(), BrandMark, SectionLabel
-    widgets.dart       NetImage, CreatorAvatar, ServiceBadge, HtmlContent, FeedView, StatusView, time helpers
+    widgets.dart       NetImage, CreatorAvatar, ServiceBadge, HtmlContent, FeedView, StatusView, BackToTop, scroll / copy / time helpers
     splash.dart        BooruPlus-style splash + revealFromBottom transition
     onboarding.dart    Four parallax slides (art lags, text leads), notification permission, optional sign-in
     home.dart          HomeScreen (floating SliverAppBar + For You / Following / Popular tabs, Popular's bottom bar) and Sidebar (drawer)
@@ -62,6 +63,10 @@ lib/
     post_page.dart     Full post: text, poll, actions, media, attachments, tags, comments
     media_viewer.dart  Full-screen viewer: every image and video in one vertical scroll, zoomable images, Chewie video
     creator_page.dart  Artist profile (banner, site, links, Follow, Similar artists sheet) + tabs; FollowButton, ArtistTile
+    creator_media.dart CreatorMediaTab: an artist's images, GIFs and videos as a filterable grid
+    tag_page.dart      TagPostsPage: posts with a tag from every artist; openTag
+    random_page.dart   RandomPage: a random post or artist, shuffle and gear buttons
+    hash_lookup_page.dart  HashLookupPage: SHA-256 pasted or worked out from a picked file
     community_page.dart CommunityChatPage: a Patreon community channel as a chat log, newest at the bottom
     backup.dart        Export / import dialogs (SAF folder and file pickers)
     settings_cards.dart BooruPlus-style settings panels (SettingsGroup, SettingsSwitchCard, SettingsChoiceCard, ...)
@@ -71,6 +76,8 @@ lib/
 test/
   for_you_test.dart         Taste, source sampling, blending and ForYouFeed over fake fetches
   core_test.dart            Parsing, URLs, entity decoding, polls, fancards, comment threads, DM / popular / similar-artist / community scraping
+  explore_test.dart         Tag page and tagged posts, random redirects, hash lookup, sha256Hex, the Random setting
+  back_to_top_test.dart     BackToTop shows after two screens and scrolls up
   backup_test.dart          Backup encoding and sealing, merges, AppState likes and their account sync
   update_checker_test.dart  UpdateChecker against a fake Pawchive (MockClient + in-memory prefs)
   downloads_test.dart       DownloadManager: URL resolution, naming, failure and retry (in-memory target)
@@ -156,8 +163,31 @@ docs/pawchive-api.md        API reference and quirks
 - **Back to top.** Tapping the open tab or the logo on Home, the open
   Popular section in the bottom bar, or the open tab or collapsed name on a
   profile calls `scrollNestedToTop`. NestedScrollView moves all its inner
-  lists together, so every tab goes up. Back on Following or Popular
+  lists together, so every tab goes up. `BackToTop` (around `FeedView`,
+  popular artists, the media grid, tags and hash results) shows a pink
+  arrow at the bottom center once a list is two screens down; it uses
+  `scrollNestedToTop` inside a NestedScrollView and `scrollToTop`
+  otherwise. Both jump to 1.5 screens first so the animation doesn't build
+  (and load thumbnails for) every row. Back on Following or Popular
   returns to For You (`PopScope` on HomeScreen) instead of leaving.
+- **Media tab.** `CreatorMediaTab` pages the artist's posts with its own
+  `OffsetFeed`, created only when the tab opens, and shows `post.media` as
+  a 3-column grid filtered All / Photos / GIFs / Videos. When a filter
+  leaves fewer than 24 tiles it loads up to 4 more pages by itself, then
+  offers "Look further". Videos use the post's first image as a poster.
+- **Tags.** Explore's Tags tab lists the site's popular tags
+  (`AppState.popularTags`, once per session, filtered on the device) under
+  a "Posts tagged #query" row for any typed tag. `TagPostsPage` scrapes
+  `/posts?tag=` (the API ignores `tag`). A tag on a post asks whether to
+  show that artist's posts or everyone's.
+- **Random.** `RandomPage` reads where `/posts/random` or `/artists/random`
+  redirects (`followRedirects = false`) and shows a `PostPage` or
+  `CreatorPage` under two FABs: shuffle, and a gear to switch kind. The
+  first visit asks which (`AppSettings.randomKind`, null until chosen).
+- **Hash lookup.** `HashLookupPage` takes a pasted SHA-256 or picks a file
+  with SAF and hashes it from `SafStream().readFileStream` with
+  `sha256Hex` (no upload), then calls `/search_hash/{hash}`; a 404 is "no
+  posts". Discord matches are only counted.
 - **Quick actions.** Holding a post in a feed opens `showPostMenu` (artist,
   like, favorite, download, copy link / text, open). Post text and comments
   are in a `SelectionArea`; posts and profiles have Copy link (`copyLink`).
@@ -167,7 +197,8 @@ docs/pawchive-api.md        API reference and quirks
   download, the video that may play). Images show the thumbnail at once and
   load the full file only while on screen, through `_FullFileGate` (two at a
   time, one second apart). The list stops scrolling while an image is
-  zoomed. Holding an image shows a Download pill under it (inside its
+  zoomed. Holding an image presses it in over the long-press time (`_hold`,
+  so the hold visibly registers) and then shows a Download pill under it (inside its
   bottom edge when there's no room on screen); sliding onto it and lifting
   downloads that file, and it stays tappable for 4 s after lifting
   elsewhere. Videos have Download and Open in browser in Chewie's ⋮ menu
diff --git a/docs/pawchive-api.md b/docs/pawchive-api.md
index 55000f2..14bdc48 100644
--- a/docs/pawchive-api.md
+++ b/docs/pawchive-api.md
@@ -42,6 +42,7 @@ applies.
 | `GET /{service}/user/{id}/fancards` | Fanbox only. `[{id, user_id, file_id, price, hash, ext, mime, size, added, ...}]` with no `path`; see Quirks. |
 | `GET /{service}/user/{id}/post/{post}/comments` | `[{id, parent_id, commenter_name, content, published}]` |
 | `GET /creators` | Every creator, about 16 MB. Only used by artist search, once per session. |
+| `GET /search_hash/{sha256}` | Hash lookup. `{hash, posts, discord_posts}`: `posts` are post objects with a short `content`, archived `file`s (with `node`) and `attachments`; `discord_posts` is a list or `null`. An unknown hash is a **404** with body `{}`. The schema also lists `mime`, `size`, `ext` and dates, which the live response leaves out. |
 | `GET /account/favorites?type=artist` | Needs the session cookie (401 otherwise). |
 | `GET /account/favorites?type=post` | The account's favorite posts, read as posts (`id`, `user`, `service`, ...). Needs the session cookie. Not checked against a live account; the schema only lists creator fields. |
 | `POST`/`DELETE /favorites/post/{service}/{creator}/{post}` | Like / unlike a post. Needs the session cookie. |
@@ -54,6 +55,9 @@ Web pages Pawress scrapes (`https://pawchive.pw`, not the API):
 | `/posts/popular?date=&period=&o=` | 50 `article.post-card` per page with `data-id`, `data-service`, `data-user`, a `post-card__header` title, a `/thumbnail/data{path}` image, `<time datetime="YYYY-MM-DD HH:MM:SS">` and "N favorites". No params means the last 24 hours. `period=day` takes any date; `week` and `month` only work with the start date the page itself links to in `#daily`, `#weekly` and `#monthly` (a week started 2026-10-27 for 2026-11-02, a month starts on the 1st). Other dates return no posts. |
 | `/{service}/user/{id}/community[/{channel}]?o=` | Patreon community chats; see Quirks. |
 | `/{service}/user/{id}/recommended` | "Similar artists": up to 50 `a.user-card` with `data-id`, `data-service` and `div.user-card__name`. No favorites or dates. |
+| `/posts/tags` | Popular tags, about 2000, most used first: `<article><a href="/posts?tag=..."><span>{tag}</span><span>{count}</span></a></article>` in `#tag-container`. |
+| `/posts?tag=&o=` | Posts with a tag, newest first, as the same `article.post-card`s as the popular page (no favorites), 50 per page with "Showing 1 - 50 of N". |
+| `/posts/random`, `/artists/random` | A **302** to a random `/{service}/user/{id}/post/{post}` or `/{service}/user/{id}`. Pawress reads `Location` without following it. |
 | `POST`/`DELETE /favorites/creator/{service}/{id}` | Needs the session cookie. |
 
 ## Quirks
@@ -109,5 +113,9 @@ Web pages Pawress scrapes (`https://pawchive.pw`, not the API):
   author. `cmsg__text` holds the HTML, followed by `a.cmsg__image` (full
   file `href`, thumbnail `img src`, sometimes Patreon's CDN) and
   `a.cmsg__embed` link previews.
+- **Tag search isn't in the API.** `/api/v1/posts?tag=` returns the plain
+  recent posts (the parameter is ignored), and `/api/v1/posts/tags`,
+  `/api/v1/posts/random` and `/api/v1/artists/random` are 404s, so the web
+  pages above are used (`parseTagPage`, `taggedPosts`, `randomPost`).
 - **Popular artists** have no endpoint either; `/artists` on the site sorts
   the same `/creators` data that Pawress sorts on the device.
diff --git a/lib/core/api.dart b/lib/core/api.dart
index 9341d07..2982d57 100644
--- a/lib/core/api.dart
+++ b/lib/core/api.dart
@@ -52,9 +52,11 @@ class PawchiveApi {
     String method,
     Uri uri, {
     Map<String, String>? headers,
+    bool followRedirects = true,
   }) async {
     final request = http.Request(method, uri)
-      ..headers.addAll(headers ?? _headers);
+      ..headers.addAll(headers ?? _headers)
+      ..followRedirects = followRedirects;
     final http.Response response;
     try {
       response = await http.Response.fromStream(
@@ -216,6 +218,60 @@ class PawchiveApi {
     }
   }
 
+  /// The site's most used tags, most used first (about 2000), read from the
+  /// `/posts/tags` web page; the API has no tag list.
+  Future<List<CreatorTag>> popularTags() async =>
+      parseTagPage(await _html('/posts/tags'));
+
+  /// Posts with [tag] across the site, newest first, read from the
+  /// `/posts?tag=` web page: the API's `/posts` ignores `tag`.
+  Future<List<Post>> taggedPosts(String tag, {int offset = 0}) async =>
+      parsePopularPage(
+        await _html('/posts', {
+          'tag': tag,
+          'o': offset == 0 ? null : '$offset',
+        }),
+      ).posts;
+
+  /// The posts holding the file with this SHA-256, or null when Pawchive
+  /// has no such file (a 404).
+  Future<HashLookup?> searchHash(String sha256) async {
+    try {
+      final json = await _get('/search_hash/${sha256.toLowerCase()}');
+      return HashLookup.fromJson(
+        json is Map<String, dynamic> ? json : const {},
+        sha256,
+      );
+    } on ApiException catch (e) {
+      if (e.status == 404) return null;
+      rethrow;
+    }
+  }
+
+  /// A random post, from where the site's `/posts/random` redirects.
+  Future<PawchiveLink> randomPost() => _random('/posts/random');
+
+  /// A random artist, from where the site's `/artists/random` redirects.
+  /// Only the id is known; the name comes from the profile.
+  Future<Creator> randomCreator() async {
+    final link = await _random('/artists/random');
+    return Creator(id: link.user, service: link.service, name: link.user);
+  }
+
+  Future<PawchiveLink> _random(String path) async {
+    final response = await _send(
+      'GET',
+      _uri(path, null, siteUrl),
+      headers: {..._headers, 'Accept': 'text/html'},
+      followRedirects: false,
+    );
+    final link = PawchiveLink.tryParse(response.headers['location'] ?? '');
+    if (link == null) {
+      throw const ApiException('Pawchive did not pick anything. Try again.');
+    }
+    return link;
+  }
+
   /// Read from the creator's "similar artists" web page.
   Future<List<Creator>> recommendedCreators(String service, String id) async =>
       parseCreatorCards(await _html('/$service/user/$id/recommended'));
@@ -372,6 +428,18 @@ PopularPage parsePopularPage(String html) {
   return PopularPage(posts, ranges);
 }
 
+final _tagCard = RegExp(
+  r'<article>\s*<a href="/posts\?tag=[^"]*">\s*<span>(.*?)</span>\s*'
+  r'<span>(\d+)</span>',
+  dotAll: true,
+);
+
+@visibleForTesting
+List<CreatorTag> parseTagPage(String html) => [
+  for (final card in _tagCard.allMatches(html))
+    CreatorTag(_text(card.group(1)!), int.parse(card.group(2)!)),
+];
+
 final _creatorCard = RegExp(
   r'<a\s+href="[^"]*"\s+class="user-card[^"]*"\s+data-id="([^"]*)"\s+'
   r'data-service="([^"]*)"(.*?)</a>',
diff --git a/lib/core/app_state.dart b/lib/core/app_state.dart
index 728c708..1a40c12 100644
--- a/lib/core/app_state.dart
+++ b/lib/core/app_state.dart
@@ -59,6 +59,7 @@ class AppState extends ChangeNotifier {
   List<UpdateNotice>? _alert;
 
   Future<List<Creator>>? _allCreators;
+  Future<List<CreatorTag>>? _popularTags;
 
   bool get signedIn => api.session != null;
   int get unreadNotices => notices.where((n) => !n.read).length;
@@ -538,6 +539,16 @@ class AppState extends ChangeNotifier {
     return pending;
   }
 
+  /// The site's popular tags, read once per session for Explore.
+  Future<List<CreatorTag>> popularTags() {
+    final pending = _popularTags ??= api.popularTags();
+    pending.catchError((Object _) {
+      _popularTags = null;
+      return <CreatorTag>[];
+    });
+    return pending;
+  }
+
   static String _files(int count) => count == 1 ? '1 file' : '$count files';
 
   void _say(String text) {
diff --git a/lib/core/file_hash.dart b/lib/core/file_hash.dart
new file mode 100644
index 0000000..175345b
--- /dev/null
+++ b/lib/core/file_hash.dart
@@ -0,0 +1,24 @@
+import 'package:cryptography/cryptography.dart';
+
+/// A SHA-256 as Pawchive's hash lookup takes it: 64 hex digits.
+bool isSha256(String text) => RegExp(r'^[0-9a-fA-F]{64}$').hasMatch(text);
+
+/// The SHA-256 of [chunks] in lowercase hex, read a chunk at a time so a
+/// large video never sits in memory whole. [onProgress] gets the bytes read
+/// so far.
+Future<String> sha256Hex(
+  Stream<List<int>> chunks, {
+  void Function(int read)? onProgress,
+}) async {
+  final sink = Sha256().newHashSink();
+  var read = 0;
+  await for (final chunk in chunks) {
+    sink.add(chunk);
+    read += chunk.length;
+    onProgress?.call(read);
+  }
+  sink.close();
+  final hash = await sink.hash();
+  return [for (final byte in hash.bytes) byte.toRadixString(16).padLeft(2, '0')]
+      .join();
+}
diff --git a/lib/core/models.dart b/lib/core/models.dart
index 8cdd25d..ae79cb1 100644
--- a/lib/core/models.dart
+++ b/lib/core/models.dart
@@ -460,6 +460,60 @@ class CreatorTag {
       CreatorTag(_str(json['tag']), _int(json['post_count']));
 }
 
+/// A post or artist page on Pawchive, as the random pages redirect to:
+/// `/{service}/user/{user}[/post/{post}]`.
+class PawchiveLink {
+  const PawchiveLink({required this.service, required this.user, this.post});
+
+  final String service;
+  final String user;
+  final String? post;
+
+  static final _pattern = RegExp(
+    r'/([\w-]+)/user/([^/?#]+)(?:/post/([^/?#]+))?',
+  );
+
+  static PawchiveLink? tryParse(String url) {
+    final match = _pattern.firstMatch(url);
+    if (match == null) return null;
+    return PawchiveLink(
+      service: match.group(1)!,
+      user: Uri.decodeComponent(match.group(2)!),
+      post: match.group(3),
+    );
+  }
+}
+
+/// What `/search_hash/{sha256}` found: the posts holding the file and how
+/// many Discord messages do (Pawress doesn't show Discord servers).
+class HashLookup {
+  const HashLookup({
+    required this.hash,
+    this.posts = const [],
+    this.discordCount = 0,
+    this.mime,
+    this.size,
+  });
+
+  final String hash;
+  final List<Post> posts;
+  final int discordCount;
+  final String? mime;
+  final int? size;
+
+  factory HashLookup.fromJson(Map<String, dynamic> json, [String hash = '']) =>
+      HashLookup(
+        hash: _optStr(json['hash']) ?? hash,
+        posts: [
+          for (final item in (json['posts'] as List? ?? const []))
+            if (item is Map<String, dynamic>) Post.fromJson(item),
+        ],
+        discordCount: (json['discord_posts'] as List? ?? const []).length,
+        mime: _optStr(json['mime']),
+        size: json['size'] == null ? null : _int(json['size']),
+      );
+}
+
 class Fancard {
   const Fancard({required this.file, this.price, this.added});
 
diff --git a/lib/core/store.dart b/lib/core/store.dart
index b023f41..7b0f69e 100644
--- a/lib/core/store.dart
+++ b/lib/core/store.dart
@@ -7,6 +7,9 @@ import 'models.dart';
 
 enum ThemeChoice { plum, amoled }
 
+/// What the sidebar's Random picks.
+enum RandomKind { post, artist }
+
 /// How much of For You comes from followed artists.
 enum ForYouMix {
   following('Following', .85),
@@ -36,6 +39,7 @@ class AppSettings {
     this.downloadFolderName,
     this.askDownloadFolder = false,
     this.checkUpdates = true,
+    this.randomKind,
   });
 
   final ThemeChoice theme;
@@ -70,6 +74,9 @@ class AppSettings {
   /// Look for a newer GitHub release when the app starts.
   final bool checkUpdates;
 
+  /// Null until Random is first opened and asks.
+  final RandomKind? randomKind;
+
   static const intervals = [15, 30, 60, 180, 360, 720];
 
   AppSettings copyWith({
@@ -85,6 +92,7 @@ class AppSettings {
     bool clearDownloadFolder = false,
     bool? askDownloadFolder,
     bool? checkUpdates,
+    RandomKind? randomKind,
   }) => AppSettings(
     theme: theme ?? this.theme,
     notificationsEnabled: notificationsEnabled ?? this.notificationsEnabled,
@@ -102,6 +110,7 @@ class AppSettings {
         : downloadFolder?.name ?? downloadFolderName,
     askDownloadFolder: askDownloadFolder ?? this.askDownloadFolder,
     checkUpdates: checkUpdates ?? this.checkUpdates,
+    randomKind: randomKind ?? this.randomKind,
   );
 
   factory AppSettings.fromJson(Map<String, dynamic> json) => AppSettings(
@@ -120,6 +129,7 @@ class AppSettings {
     downloadFolderName: json['downloadFolderName'] as String?,
     askDownloadFolder: json['askDownloadFolder'] as bool? ?? false,
     checkUpdates: json['checkUpdates'] as bool? ?? true,
+    randomKind: RandomKind.values.asNameMap()[json['randomKind']],
   );
 
   Map<String, dynamic> toJson() => {
@@ -135,6 +145,7 @@ class AppSettings {
     'downloadFolderName': downloadFolderName,
     'askDownloadFolder': askDownloadFolder,
     'checkUpdates': checkUpdates,
+    'randomKind': randomKind?.name,
   };
 }
 
diff --git a/lib/ui/creator_media.dart b/lib/ui/creator_media.dart
new file mode 100644
index 0000000..853c62e
--- /dev/null
+++ b/lib/ui/creator_media.dart
@@ -0,0 +1,273 @@
+import 'package:flutter/material.dart';
+
+import '../core/feeds.dart';
+import '../core/models.dart';
+import 'app_scope.dart';
+import 'post_card.dart';
+import 'theme.dart';
+import 'widgets.dart';
+
+enum _MediaFilter {
+  all('All'),
+  photos('Photos'),
+  gifs('GIFs'),
+  videos('Videos');
+
+  const _MediaFilter(this.label);
+
+  final String label;
+
+  bool matches(MediaFile file) => switch (this) {
+    _MediaFilter.all => true,
+    _MediaFilter.photos => file.isImage && file.extension != 'gif',
+    _MediaFilter.gifs => file.extension == 'gif',
+    _MediaFilter.videos => file.isVideo,
+  };
+}
+
+/// Every image, GIF and video from an artist's posts as a grid, filtered by
+/// kind. It pages through the artist's posts like the Posts tab, but only
+/// once the tab is opened.
+class CreatorMediaTab extends StatefulWidget {
+  const CreatorMediaTab({super.key, required this.creator});
+
+  final Creator creator;
+
+  @override
+  State<CreatorMediaTab> createState() => _CreatorMediaTabState();
+}
+
+class _CreatorMediaTabState extends State<CreatorMediaTab>
+    with AutomaticKeepAliveClientMixin {
+  late final OffsetFeed _feed = _postFeed();
+  _MediaFilter _filter = _MediaFilter.all;
+
+  /// Pages loaded on their own because the filter left too little to
+  /// scroll; capped so an artist without videos isn't read to the end.
+  int _autoLoads = 0;
+  static const _maxAutoLoads = 4;
+  static const _fill = 24;
+
+  @override
+  bool get wantKeepAlive => true;
+
+  OffsetFeed _postFeed() {
+    final api = AppScope.read(context).api;
+    final c = widget.creator;
+    return OffsetFeed(
+      (offset) => api.creatorPosts(c.service, c.id, offset: offset),
+    );
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    _feed.refresh();
+  }
+
+  @override
+  void dispose() {
+    _feed.dispose();
+    super.dispose();
+  }
+
+  bool _onScroll(ScrollNotification notification) {
+    if (notification.depth == 0 && notification.metrics.extentAfter < 1200) {
+      _feed.loadMore();
+    }
+    return false;
+  }
+
+  void _setFilter(_MediaFilter filter) => setState(() {
+    _filter = filter;
+    _autoLoads = 0;
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    super.build(context);
+    final handle = NestedScrollView.sliverOverlapAbsorberHandleFor(context);
+    return ListenableBuilder(
+      listenable: _feed,
+      builder: (context, _) {
+        final items = [
+          for (final post in _feed.posts)
+            for (final file in post.media)
+              if (_filter.matches(file)) (post: post, file: file),
+        ];
+        if (items.length < _fill &&
+            _autoLoads < _maxAutoLoads &&
+            !_feed.loading &&
+            !_feed.done &&
+            _feed.error == null &&
+            _feed.posts.isNotEmpty) {
+          _autoLoads++;
+          WidgetsBinding.instance.addPostFrameCallback((_) {
+            if (mounted) _feed.loadMore();
+          });
+        }
+        return BackToTop(
+          child: RefreshIndicator(
+            onRefresh: () {
+              _autoLoads = 0;
+              return _feed.refresh();
+            },
+            edgeOffset: 100,
+            child: NotificationListener<ScrollNotification>(
+              onNotification: _onScroll,
+              child: CustomScrollView(
+                key: const PageStorageKey('creator-media'),
+                physics: const AlwaysScrollableScrollPhysics(),
+                slivers: [
+                  SliverOverlapInjector(handle: handle),
+                  SliverToBoxAdapter(child: _filters()),
+                  SliverGrid.builder(
+                    gridDelegate:
+                        const SliverGridDelegateWithFixedCrossAxisCount(
+                          crossAxisCount: 3,
+                          mainAxisSpacing: 2,
+                          crossAxisSpacing: 2,
+                        ),
+                    itemCount: items.length,
+                    itemBuilder: (context, index) => _MediaCell(
+                      post: items[index].post,
+                      file: items[index].file,
+                    ),
+                  ),
+                  SliverToBoxAdapter(child: _footer(items.isEmpty)),
+                ],
+              ),
+            ),
+          ),
+        );
+      },
+    );
+  }
+
+  Widget _filters() => SingleChildScrollView(
+    scrollDirection: Axis.horizontal,
+    padding: const EdgeInsets.fromLTRB(14, 10, 14, 10),
+    child: Row(
+      children: [
+        for (final filter in _MediaFilter.values)
+          Padding(
+            padding: const EdgeInsets.only(right: 8),
+            child: ChoiceChip(
+              label: Text(filter.label),
+              selected: _filter == filter,
+              onSelected: (_) => _setFilter(filter),
+            ),
+          ),
+      ],
+    ),
+  );
+
+  Widget _footer(bool empty) {
+    final feed = _feed;
+    if (feed.error != null) {
+      return StatusView(
+        icon: Icons.cloud_off_rounded,
+        title: empty ? 'Could not load media' : 'Could not load more',
+        body: feed.error,
+        action: 'Try again',
+        onAction: feed.posts.isEmpty ? feed.refresh : feed.loadMore,
+      );
+    }
+    if (feed.loading) {
+      return const Padding(
+        padding: EdgeInsets.all(32),
+        child: Center(child: CircularProgressIndicator()),
+      );
+    }
+    if (!feed.done) {
+      // Auto-loading stopped short; let the user keep looking.
+      return Padding(
+        padding: const EdgeInsets.fromLTRB(16, 20, 16, 96),
+        child: Center(
+          child: OutlinedButton.icon(
+            onPressed: feed.loadMore,
+            icon: const Icon(Icons.expand_more_rounded),
+            label: Text(
+              empty
+                  ? 'No ${_filter.label.toLowerCase()} yet. Look further'
+                  : 'Load more',
+            ),
+          ),
+        ),
+      );
+    }
+    if (empty) {
+      return StatusView(
+        icon: Icons.perm_media_outlined,
+        title: _filter == _MediaFilter.all
+            ? 'No media'
+            : 'No ${_filter.label.toLowerCase()}',
+      );
+    }
+    return const SizedBox(height: 96);
+  }
+}
+
+/// A square tile: the image's thumbnail, or for a video the post's first
+/// image as a poster (videos have no thumbnails). Tapping opens the viewer
+/// at this file; holding opens the post's quick actions.
+class _MediaCell extends StatelessWidget {
+  const _MediaCell({required this.post, required this.file});
+
+  final Post post;
+  final MediaFile file;
+
+  @override
+  Widget build(BuildContext context) {
+    final poster =
+        file.thumbnailUrl ??
+        post.media.where((m) => m.isImage).firstOrNull?.thumbnailUrl;
+    return GestureDetector(
+      onTap: () => openViewer(context, post, file),
+      onLongPress: () => showPostMenu(context, post),
+      child: Stack(
+        fit: StackFit.expand,
+        children: [
+          poster != null
+              ? NetImage(poster)
+              : ColoredBox(color: pawPlum.withValues(alpha: .6)),
+          if (file.isVideo)
+            Center(
+              child: Container(
+                padding: const EdgeInsets.all(6),
+                decoration: BoxDecoration(
+                  color: Colors.black.withValues(alpha: .55),
+                  shape: BoxShape.circle,
+                ),
+                child: const Icon(
+                  Icons.play_arrow_rounded,
+                  color: Colors.white,
+                  size: 26,
+                ),
+              ),
+            ),
+          if (file.extension == 'gif')
+            Positioned(
+              left: 6,
+              bottom: 6,
+              child: Container(
+                padding: const EdgeInsets.symmetric(horizontal: 5, vertical: 1),
+                decoration: BoxDecoration(
+                  color: Colors.black.withValues(alpha: .7),
+                  borderRadius: BorderRadius.circular(4),
+                ),
+                child: const Text(
+                  'GIF',
+                  style: TextStyle(
+                    fontSize: 10,
+                    fontWeight: FontWeight.w800,
+                    color: Colors.white,
+                  ),
+                ),
+              ),
+            ),
+        ],
+      ),
+    );
+  }
+}
diff --git a/lib/ui/creator_page.dart b/lib/ui/creator_page.dart
index affe0f4..339162e 100644
--- a/lib/ui/creator_page.dart
+++ b/lib/ui/creator_page.dart
@@ -5,13 +5,14 @@ import '../core/feeds.dart';
 import '../core/models.dart';
 import 'app_scope.dart';
 import 'community_page.dart';
+import 'creator_media.dart';
 import 'notify_bell.dart';
 import 'post_card.dart';
 import 'theme.dart';
 import 'widgets.dart';
 
 /// An artist's profile: banner, original site, linked accounts and a Follow
-/// button, then tabs for posts, announcements, tags, DMs, (Patreon only)
+/// button, then tabs for posts, media, announcements, tags, DMs, (Patreon only)
 /// community chats and (Fanbox only) fancards.
 class CreatorPage extends StatefulWidget {
   const CreatorPage({super.key, required this.creator, this.initialTag});
@@ -42,6 +43,7 @@ class _CreatorPageState extends State<CreatorPage>
 
   List<String> get _tabLabels => [
     'Posts',
+    'Media',
     'Announcements',
     'Tags',
     'DMs',
@@ -242,6 +244,7 @@ class _CreatorPageState extends State<CreatorPage>
                       ),
               ),
             ),
+            CreatorMediaTab(creator: widget.creator),
             _FutureList<Announcement>(
               load: () =>
                   AppScope.read(context).api.announcements(c.service, c.id),
diff --git a/lib/ui/hash_lookup_page.dart b/lib/ui/hash_lookup_page.dart
new file mode 100644
index 0000000..7d21204
--- /dev/null
+++ b/lib/ui/hash_lookup_page.dart
@@ -0,0 +1,241 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:saf_stream/saf_stream.dart';
+import 'package:saf_util/saf_util.dart';
+
+import '../core/api.dart';
+import '../core/file_hash.dart';
+import '../core/models.dart';
+import 'app_scope.dart';
+import 'post_card.dart';
+import 'theme.dart';
+import 'widgets.dart';
+
+/// Finds the posts that hold a file, like the site's hash search: paste a
+/// SHA-256, or pick a file and Pawress hashes it on the device (the file is
+/// never uploaded).
+class HashLookupPage extends StatefulWidget {
+  const HashLookupPage({super.key});
+
+  @override
+  State<HashLookupPage> createState() => _HashLookupPageState();
+}
+
+class _HashLookupPageState extends State<HashLookupPage> {
+  final _field = TextEditingController();
+
+  /// While hashing a picked file: its name and how far along.
+  ({String name, double? progress})? _hashing;
+  bool _searching = false;
+  String? _error;
+
+  /// The last lookup; `result` is null when Pawchive has no such file.
+  ({String hash, HashLookup? result})? _lookup;
+
+  @override
+  void dispose() {
+    _field.dispose();
+    super.dispose();
+  }
+
+  Future<void> _paste() async {
+    final data = await Clipboard.getData(Clipboard.kTextPlain);
+    final text = data?.text?.trim();
+    if (text == null || text.isEmpty) return;
+    _field.text = text;
+    if (isSha256(text)) await _search(text);
+  }
+
+  Future<void> _pickFile() async {
+    final file = await SafUtil().pickFile();
+    if (file == null || !mounted) return;
+    setState(() {
+      _hashing = (name: file.name, progress: file.length > 0 ? 0 : null);
+      _error = null;
+    });
+    try {
+      var shown = 0.0;
+      final hash = await sha256Hex(
+        await SafStream().readFileStream(file.uri),
+        onProgress: (read) {
+          if (file.length <= 0 || !mounted) return;
+          final progress = (read / file.length).clamp(0.0, 1.0);
+          // Repaint every percent, not every chunk.
+          if (progress - shown < .01 && progress < 1) return;
+          shown = progress;
+          setState(() => _hashing = (name: file.name, progress: progress));
+        },
+      );
+      if (!mounted) return;
+      setState(() => _hashing = null);
+      _field.text = hash;
+      await _search(hash);
+    } catch (_) {
+      if (mounted) {
+        setState(() {
+          _hashing = null;
+          _error = 'Could not read ${file.name}.';
+        });
+      }
+    }
+  }
+
+  Future<void> _search([String? text]) async {
+    final hash = (text ?? _field.text).trim().toLowerCase();
+    FocusScope.of(context).unfocus();
+    if (!isSha256(hash)) {
+      setState(() => _error = 'A SHA-256 hash is 64 characters, 0-9 and a-f.');
+      return;
+    }
+    setState(() {
+      _searching = true;
+      _error = null;
+    });
+    try {
+      final result = await AppScope.read(context).api.searchHash(hash);
+      if (mounted) setState(() => _lookup = (hash: hash, result: result));
+    } on ApiException catch (e) {
+      if (mounted) setState(() => _error = e.message);
+    } finally {
+      if (mounted) setState(() => _searching = false);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final busy = _searching || _hashing != null;
+    final hashing = _hashing;
+    final lookup = _lookup;
+    final result = lookup?.result;
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text(
+          'Hash lookup',
+          style: TextStyle(fontWeight: FontWeight.w700),
+        ),
+      ),
+      body: BackToTop(
+        child: ListView(
+          padding: const EdgeInsets.only(bottom: 96),
+          children: [
+            Padding(
+              padding: const EdgeInsets.fromLTRB(16, 8, 16, 0),
+              child: Text(
+                'Find the posts a file came from. Paste its SHA-256 hash, or '
+                'choose the file and Pawress works the hash out on this '
+                'phone; the file itself is never uploaded.',
+                style: TextStyle(color: ink(.6), height: 1.4),
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.fromLTRB(16, 16, 16, 0),
+              child: TextField(
+                controller: _field,
+                enabled: !busy,
+                maxLines: 2,
+                minLines: 1,
+                textInputAction: TextInputAction.search,
+                style: const TextStyle(fontFamily: 'monospace', fontSize: 14),
+                decoration: InputDecoration(
+                  hintText: 'SHA-256 hash',
+                  prefixIcon: const Icon(Icons.tag_rounded),
+                  suffixIcon: IconButton(
+                    tooltip: 'Paste',
+                    icon: const Icon(Icons.content_paste_rounded),
+                    onPressed: busy ? null : _paste,
+                  ),
+                ),
+                onSubmitted: (_) => _search(),
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.fromLTRB(16, 12, 16, 0),
+              child: Row(
+                children: [
+                  Expanded(
+                    child: FilledButton.icon(
+                      onPressed: busy ? null : _search,
+                      icon: const Icon(Icons.search_rounded),
+                      label: const Text('Look up'),
+                    ),
+                  ),
+                  const SizedBox(width: 12),
+                  Expanded(
+                    child: OutlinedButton.icon(
+                      onPressed: busy ? null : _pickFile,
+                      icon: const Icon(Icons.upload_file_rounded),
+                      label: const Text('Choose file'),
+                    ),
+                  ),
+                ],
+              ),
+            ),
+            if (hashing != null)
+              Padding(
+                padding: const EdgeInsets.fromLTRB(16, 20, 16, 0),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      'Hashing ${hashing.name}…',
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                      style: TextStyle(color: ink(.7)),
+                    ),
+                    const SizedBox(height: 8),
+                    LinearProgressIndicator(value: hashing.progress),
+                  ],
+                ),
+              ),
+            if (_searching)
+              const Padding(
+                padding: EdgeInsets.all(32),
+                child: Center(child: CircularProgressIndicator()),
+              ),
+            if (_error != null)
+              Padding(
+                padding: const EdgeInsets.fromLTRB(16, 16, 16, 0),
+                child: Text(
+                  _error!,
+                  style: TextStyle(color: Theme.of(context).colorScheme.error),
+                ),
+              ),
+            if (lookup != null && !_searching) ...[
+              if (result == null || result.posts.isEmpty)
+                StatusView(
+                  icon: Icons.search_off_rounded,
+                  title: 'No posts have this file',
+                  body: result != null && result.discordCount > 0
+                      ? 'It is only in ${_messages(result.discordCount)} on '
+                            'Discord.'
+                      : 'Pawchive has no file with this hash.',
+                )
+              else ...[
+                SectionLabel(
+                  result.posts.length == 1
+                      ? 'Found in 1 post'
+                      : 'Found in ${result.posts.length} posts',
+                ),
+                if (result.discordCount > 0)
+                  Padding(
+                    padding: const EdgeInsets.fromLTRB(16, 0, 16, 8),
+                    child: Text(
+                      'Also in ${_messages(result.discordCount)} on Discord.',
+                      style: TextStyle(color: ink(.5)),
+                    ),
+                  ),
+                for (final post in result.posts) ...[
+                  PostCard(post),
+                  const Divider(),
+                ],
+              ],
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+
+  static String _messages(int count) =>
+      count == 1 ? '1 message' : '$count messages';
+}
diff --git a/lib/ui/home.dart b/lib/ui/home.dart
index 73fdf94..860eedb 100644
--- a/lib/ui/home.dart
+++ b/lib/ui/home.dart
@@ -12,10 +12,12 @@ import 'update_dialog.dart';
 import 'downloads.dart';
 import 'favorites_page.dart';
 import 'following_page.dart';
+import 'hash_lookup_page.dart';
 import 'login_page.dart';
 import 'notifications_page.dart';
 import 'popular.dart';
 import 'post_card.dart';
+import 'random_page.dart';
 import 'search_page.dart';
 import 'settings_page.dart';
 import 'theme.dart';
@@ -435,103 +437,127 @@ class Sidebar extends StatelessWidget {
       onOpen(builder);
     }
 
+    // Scrolls on short screens; the logo stays at the bottom otherwise.
     return Drawer(
       child: SafeArea(
-        child: Column(
-          crossAxisAlignment: CrossAxisAlignment.start,
-          children: [
-            Padding(
-              padding: const EdgeInsets.fromLTRB(20, 20, 20, 12),
+        child: CustomScrollView(
+          slivers: [
+            SliverToBoxAdapter(
               child: Column(
                 crossAxisAlignment: CrossAxisAlignment.start,
                 children: [
-                  const _AccountAvatar(size: 44),
-                  const SizedBox(height: 12),
-                  Text(
-                    state.signedIn
-                        ? (state.accountName ?? 'Pawchive account')
-                        : 'Guest',
-                    style: const TextStyle(
-                      fontSize: 18,
-                      fontWeight: FontWeight.w800,
+                  Padding(
+                    padding: const EdgeInsets.fromLTRB(20, 20, 20, 12),
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        const _AccountAvatar(size: 44),
+                        const SizedBox(height: 12),
+                        Text(
+                          state.signedIn
+                              ? (state.accountName ?? 'Pawchive account')
+                              : 'Guest',
+                          style: const TextStyle(
+                            fontSize: 18,
+                            fontWeight: FontWeight.w800,
+                          ),
+                        ),
+                        Text(
+                          state.signedIn
+                              ? 'Signed in to Pawchive'
+                              : 'Follows are saved on this device',
+                          style: TextStyle(color: ink(.5)),
+                        ),
+                        const SizedBox(height: 12),
+                        GestureDetector(
+                          onTap: () => open((_) => const FollowingPage()),
+                          child: Text.rich(
+                            TextSpan(
+                              children: [
+                                TextSpan(
+                                  text: '${state.follows.length}',
+                                  style: const TextStyle(
+                                    fontWeight: FontWeight.w800,
+                                  ),
+                                ),
+                                TextSpan(
+                                  text: ' Following',
+                                  style: TextStyle(color: ink(.55)),
+                                ),
+                              ],
+                            ),
+                          ),
+                        ),
+                      ],
                     ),
                   ),
-                  Text(
-                    state.signedIn
-                        ? 'Signed in to Pawchive'
-                        : 'Follows are saved on this device',
-                    style: TextStyle(color: ink(.5)),
+                  const Divider(),
+                  _SidebarItem(
+                    icon: Icons.person_outline_rounded,
+                    label: state.signedIn ? 'Account' : 'Sign in',
+                    onTap: () => state.signedIn
+                        ? open((_) => const SettingsPage())
+                        : open((_) => const LoginPage()),
                   ),
-                  const SizedBox(height: 12),
-                  GestureDetector(
+                  _SidebarItem(
+                    icon: Icons.people_outline_rounded,
+                    label: 'Following',
                     onTap: () => open((_) => const FollowingPage()),
-                    child: Text.rich(
-                      TextSpan(
-                        children: [
-                          TextSpan(
-                            text: '${state.follows.length}',
-                            style: const TextStyle(fontWeight: FontWeight.w800),
-                          ),
-                          TextSpan(
-                            text: ' Following',
-                            style: TextStyle(color: ink(.55)),
-                          ),
-                        ],
-                      ),
+                  ),
+                  _SidebarItem(
+                    icon: Icons.favorite_border_rounded,
+                    label: 'Favorites',
+                    onTap: () => open((_) => const FavoritesPage()),
+                  ),
+                  _SidebarItem(
+                    icon: Icons.notifications_none_rounded,
+                    label: 'Notifications',
+                    badge: state.unreadNotices,
+                    onTap: () => open((_) => const NotificationsPage()),
+                  ),
+                  _SidebarItem(
+                    icon: Icons.search_rounded,
+                    label: 'Explore',
+                    onTap: () => open((_) => const SearchPage()),
+                  ),
+                  _SidebarItem(
+                    icon: Icons.shuffle_rounded,
+                    label: 'Random',
+                    onTap: () => open((_) => const RandomPage()),
+                  ),
+                  _SidebarItem(
+                    icon: Icons.fingerprint_rounded,
+                    label: 'Hash lookup',
+                    onTap: () => open((_) => const HashLookupPage()),
+                  ),
+                  ListenableBuilder(
+                    listenable: state.downloads,
+                    builder: (context, _) => _SidebarItem(
+                      icon: Icons.download_rounded,
+                      label: 'Downloads',
+                      badge: state.downloads.active,
+                      onTap: () => open((_) => const DownloadsPage()),
                     ),
                   ),
+                  const Divider(),
+                  _SidebarItem(
+                    icon: Icons.settings_outlined,
+                    label: 'Settings',
+                    onTap: () => open((_) => const SettingsPage()),
+                  ),
                 ],
               ),
             ),
-            const Divider(),
-            _SidebarItem(
-              icon: Icons.person_outline_rounded,
-              label: state.signedIn ? 'Account' : 'Sign in',
-              onTap: () => state.signedIn
-                  ? open((_) => const SettingsPage())
-                  : open((_) => const LoginPage()),
-            ),
-            _SidebarItem(
-              icon: Icons.people_outline_rounded,
-              label: 'Following',
-              onTap: () => open((_) => const FollowingPage()),
-            ),
-            _SidebarItem(
-              icon: Icons.favorite_border_rounded,
-              label: 'Favorites',
-              onTap: () => open((_) => const FavoritesPage()),
-            ),
-            _SidebarItem(
-              icon: Icons.notifications_none_rounded,
-              label: 'Notifications',
-              badge: state.unreadNotices,
-              onTap: () => open((_) => const NotificationsPage()),
-            ),
-            _SidebarItem(
-              icon: Icons.search_rounded,
-              label: 'Explore',
-              onTap: () => open((_) => const SearchPage()),
-            ),
-            ListenableBuilder(
-              listenable: state.downloads,
-              builder: (context, _) => _SidebarItem(
-                icon: Icons.download_rounded,
-                label: 'Downloads',
-                badge: state.downloads.active,
-                onTap: () => open((_) => const DownloadsPage()),
+            SliverFillRemaining(
+              hasScrollBody: false,
+              child: Align(
+                alignment: Alignment.bottomLeft,
+                child: Padding(
+                  padding: const EdgeInsets.all(20),
+                  child: Image.asset(logoAsset, height: 22),
+                ),
               ),
             ),
-            const Divider(),
-            _SidebarItem(
-              icon: Icons.settings_outlined,
-              label: 'Settings',
-              onTap: () => open((_) => const SettingsPage()),
-            ),
-            const Spacer(),
-            Padding(
-              padding: const EdgeInsets.all(20),
-              child: Image.asset(logoAsset, height: 22),
-            ),
           ],
         ),
       ),
diff --git a/lib/ui/media_viewer.dart b/lib/ui/media_viewer.dart
index 7b654b3..a275c02 100644
--- a/lib/ui/media_viewer.dart
+++ b/lib/ui/media_viewer.dart
@@ -3,6 +3,7 @@ import 'dart:math' as math;
 
 import 'package:chewie/chewie.dart';
 import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:video_player/video_player.dart';
@@ -37,7 +38,8 @@ class MediaViewer extends StatefulWidget {
   State<MediaViewer> createState() => _MediaViewerState();
 }
 
-class _MediaViewerState extends State<MediaViewer> {
+class _MediaViewerState extends State<MediaViewer>
+    with SingleTickerProviderStateMixin {
   late List<MediaFile> _media = widget.post.media;
   late int _index = widget.initialIndex;
   final _centerKey = UniqueKey();
@@ -58,6 +60,22 @@ class _MediaViewerState extends State<MediaViewer> {
   Timer? _pressLinger;
   static const _pressSize = Size(176, 48);
 
+  /// Presses the touched image in while the finger stays on it, over the
+  /// time a long press takes, so holding visibly does something.
+  late final _hold = AnimationController(
+    vsync: this,
+    duration: kLongPressTimeout,
+    reverseDuration: const Duration(milliseconds: 260),
+  );
+  late final _holdScale = Tween<double>(begin: 1, end: .94).animate(
+    CurvedAnimation(
+      parent: _hold,
+      curve: Curves.easeIn,
+      reverseCurve: Curves.easeOutBack.flipped,
+    ),
+  );
+  int? _held;
+
   @override
   void initState() {
     super.initState();
@@ -114,6 +132,7 @@ class _MediaViewerState extends State<MediaViewer> {
 
   @override
   void dispose() {
+    _hold.dispose();
     _pressLinger?.cancel();
     _scroll?.dispose();
     super.dispose();
@@ -163,7 +182,15 @@ class _MediaViewerState extends State<MediaViewer> {
     setState(() => _pressHover = hover);
   }
 
+  void _holdDown(int index) {
+    if (_held != index) setState(() => _held = index);
+    _hold.forward();
+  }
+
+  void _holdUp() => _hold.reverse();
+
   void _endPress(LongPressEndDetails details) {
+    _holdUp();
     if (_overPress(details.globalPosition)) {
       _pressDownload();
       return;
@@ -214,17 +241,24 @@ class _MediaViewerState extends State<MediaViewer> {
             if (_press != null) return _dismissPress();
             setState(() => _chrome = !_chrome);
           },
+          onLongPressDown: (_) => _holdDown(index),
+          onLongPressCancel: _holdUp,
           onLongPressStart: (_) => _startPress(index, itemContext),
           onLongPressMoveUpdate: _movePress,
           onLongPressEnd: _endPress,
-          child: _ImageItem(
-            key: ValueKey(item.path),
-            file: item,
-            gate: _gate,
-            loadFull: !_resolving && _visible.containsKey(index),
-            onZoom: (zoomed) {
-              if (zoomed != _zoomed) setState(() => _zoomed = zoomed);
-            },
+          child: ScaleTransition(
+            scale: index == _held
+                ? _holdScale
+                : const AlwaysStoppedAnimation(1.0),
+            child: _ImageItem(
+              key: ValueKey(item.path),
+              file: item,
+              gate: _gate,
+              loadFull: !_resolving && _visible.containsKey(index),
+              onZoom: (zoomed) {
+                if (zoomed != _zoomed) setState(() => _zoomed = zoomed);
+              },
+            ),
           ),
         ),
       );
diff --git a/lib/ui/popular.dart b/lib/ui/popular.dart
index 5ab1ca7..d701c86 100644
--- a/lib/ui/popular.dart
+++ b/lib/ui/popular.dart
@@ -180,14 +180,16 @@ class _PopularTabState extends State<PopularTab>
             separatorBuilder: (_, _) => const Divider(),
           );
         }
-        return CustomScrollView(
-          key: const PageStorageKey('popular-artists'),
-          slivers: [
-            SliverOverlapInjector(handle: handle),
-            if (snapshot.hasData) SliverToBoxAdapter(child: _artistFilters()),
-            body,
-            const SliverToBoxAdapter(child: SizedBox(height: 96)),
-          ],
+        return BackToTop(
+          child: CustomScrollView(
+            key: const PageStorageKey('popular-artists'),
+            slivers: [
+              SliverOverlapInjector(handle: handle),
+              if (snapshot.hasData) SliverToBoxAdapter(child: _artistFilters()),
+              body,
+              const SliverToBoxAdapter(child: SizedBox(height: 96)),
+            ],
+          ),
         );
       },
     );
diff --git a/lib/ui/post_page.dart b/lib/ui/post_page.dart
index aa8e6dd..d6854b2 100644
--- a/lib/ui/post_page.dart
+++ b/lib/ui/post_page.dart
@@ -8,6 +8,7 @@ import 'downloads.dart';
 import 'creator_page.dart';
 import 'poll.dart';
 import 'post_card.dart';
+import 'tag_page.dart';
 import 'theme.dart';
 import 'widgets.dart';
 
@@ -87,6 +88,39 @@ class _PostPageState extends State<PostPage> {
     });
   }
 
+  /// A post's tag can mean this artist's posts or everyone's.
+  Future<void> _openTag(Creator creator, String tag) async {
+    final everyone = await showModalBottomSheet<bool>(
+      context: context,
+      useSafeArea: true,
+      showDragHandle: true,
+      backgroundColor: canvas,
+      builder: (sheet) => Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          ListTile(
+            leading: CreatorAvatar(creator, size: 32),
+            title: Text('#$tag from ${creator.name}'),
+            onTap: () => Navigator.of(sheet).pop(false),
+          ),
+          ListTile(
+            leading: const Icon(Icons.public_rounded),
+            title: Text('#$tag from every artist'),
+            onTap: () => Navigator.of(sheet).pop(true),
+          ),
+          const SizedBox(height: 12),
+        ],
+      ),
+    );
+    if (everyone == null || !mounted) return;
+    if (everyone) return openTag(context, tag);
+    await Navigator.of(context).push(
+      MaterialPageRoute<void>(
+        builder: (_) => CreatorPage(creator: creator, initialTag: tag),
+      ),
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     final post = _post;
@@ -247,12 +281,7 @@ class _PostPageState extends State<PostPage> {
                 for (final tag in post.tags)
                   ActionChip(
                     label: Text('#$tag'),
-                    onPressed: () => Navigator.of(context).push(
-                      MaterialPageRoute<void>(
-                        builder: (_) =>
-                            CreatorPage(creator: creator, initialTag: tag),
-                      ),
-                    ),
+                    onPressed: () => _openTag(creator, tag),
                   ),
               ],
             ),
diff --git a/lib/ui/random_page.dart b/lib/ui/random_page.dart
new file mode 100644
index 0000000..26465b2
--- /dev/null
+++ b/lib/ui/random_page.dart
@@ -0,0 +1,207 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+import '../core/api.dart';
+import '../core/store.dart';
+import 'app_scope.dart';
+import 'creator_page.dart';
+import 'post_page.dart';
+import 'theme.dart';
+import 'widgets.dart';
+
+/// A random post or artist (as the site's random links pick them), with a
+/// shuffle button to pick again and a gear to switch between the two. The
+/// first visit asks which; the choice is kept in [AppSettings.randomKind].
+class RandomPage extends StatefulWidget {
+  const RandomPage({super.key});
+
+  @override
+  State<RandomPage> createState() => _RandomPageState();
+}
+
+class _RandomPageState extends State<RandomPage> {
+  late RandomKind? _kind = AppScope.read(context).settings.randomKind;
+  Widget? _shown;
+  bool _loading = false;
+  String? _error;
+
+  /// Keys each pick so a new one starts fresh instead of reusing state.
+  int _round = 0;
+
+  @override
+  void initState() {
+    super.initState();
+    if (_kind == null) {
+      WidgetsBinding.instance.addPostFrameCallback((_) => _choose(first: true));
+    } else {
+      _roll();
+    }
+  }
+
+  Future<void> _roll() async {
+    final kind = _kind;
+    if (kind == null || _loading) return;
+    setState(() {
+      _loading = true;
+      _error = null;
+    });
+    final state = AppScope.read(context);
+    final api = state.api;
+    try {
+      final Widget page;
+      switch (kind) {
+        case RandomKind.post:
+          final link = await api.randomPost();
+          final post = link.post;
+          if (post == null) {
+            throw const ApiException('Pawchive did not pick a post.');
+          }
+          page = PostPage(
+            key: ValueKey(++_round),
+            service: link.service,
+            creatorId: link.user,
+            postId: post,
+          );
+        case RandomKind.artist:
+          final creator = await api.randomCreator();
+          final known = state.directory.known(creator.key);
+          page = CreatorPage(
+            key: ValueKey(++_round),
+            creator: known ?? creator,
+          );
+      }
+      if (!mounted) return;
+      HapticFeedback.selectionClick();
+      setState(() => _shown = page);
+    } on ApiException catch (e) {
+      if (!mounted) return;
+      if (_shown == null) {
+        setState(() => _error = e.message);
+      } else {
+        ScaffoldMessenger.of(context)
+          ..hideCurrentSnackBar()
+          ..showSnackBar(SnackBar(content: Text(e.message)));
+      }
+    } finally {
+      if (mounted) setState(() => _loading = false);
+    }
+  }
+
+  /// Asks posts or artists. Dismissing the first ask leaves the page.
+  Future<void> _choose({bool first = false}) async {
+    final state = AppScope.read(context);
+    final kind = await showModalBottomSheet<RandomKind>(
+      context: context,
+      useSafeArea: true,
+      showDragHandle: true,
+      backgroundColor: canvas,
+      builder: (sheet) => Column(
+        mainAxisSize: MainAxisSize.min,
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          const Padding(
+            padding: EdgeInsets.fromLTRB(20, 0, 20, 8),
+            child: Text(
+              'What should Random pick?',
+              style: TextStyle(fontSize: 17, fontWeight: FontWeight.w800),
+            ),
+          ),
+          for (final (kind, icon, label, detail) in const [
+            (
+              RandomKind.post,
+              Icons.article_outlined,
+              'Posts',
+              'A random post from any artist',
+            ),
+            (
+              RandomKind.artist,
+              Icons.person_outline_rounded,
+              'Artists',
+              'A random artist profile',
+            ),
+          ])
+            ListTile(
+              contentPadding: const EdgeInsets.symmetric(horizontal: 20),
+              leading: Icon(icon),
+              title: Text(label),
+              subtitle: Text(detail, style: TextStyle(color: ink(.5))),
+              trailing: _kind == kind
+                  ? const Icon(Icons.check_rounded, color: pawPink)
+                  : null,
+              onTap: () => Navigator.of(sheet).pop(kind),
+            ),
+          const SizedBox(height: 12),
+        ],
+      ),
+    );
+    if (!mounted) return;
+    if (kind == null) {
+      if (first) Navigator.of(context).maybePop();
+      return;
+    }
+    final changed = kind != _kind;
+    _kind = kind;
+    await state.updateSettings(state.settings.copyWith(randomKind: kind));
+    if (changed || _shown == null) await _roll();
+  }
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+    body:
+        _shown ??
+        Scaffold(
+          appBar: AppBar(
+            title: const Text(
+              'Random',
+              style: TextStyle(fontWeight: FontWeight.w700),
+            ),
+          ),
+          body: Center(
+            child: _error != null
+                ? StatusView(
+                    icon: Icons.cloud_off_rounded,
+                    title: 'Could not pick one',
+                    body: _error,
+                    action: 'Try again',
+                    onAction: _roll,
+                  )
+                : const CircularProgressIndicator(),
+          ),
+        ),
+    floatingActionButton: Column(
+      mainAxisSize: MainAxisSize.min,
+      crossAxisAlignment: CrossAxisAlignment.end,
+      children: [
+        FloatingActionButton.small(
+          heroTag: 'random-kind',
+          tooltip: _kind == RandomKind.artist
+              ? 'Picking artists'
+              : 'Picking posts',
+          backgroundColor: panel,
+          foregroundColor: ink(.85),
+          onPressed: _choose,
+          child: const Icon(Icons.settings_rounded),
+        ),
+        const SizedBox(height: 12),
+        FloatingActionButton(
+          heroTag: 'random-roll',
+          tooltip: _kind == RandomKind.artist
+              ? 'Another artist'
+              : 'Another post',
+          backgroundColor: pawPink,
+          foregroundColor: pawOutline,
+          onPressed: _kind == null ? null : _roll,
+          child: _loading
+              ? const SizedBox.square(
+                  dimension: 22,
+                  child: CircularProgressIndicator(
+                    strokeWidth: 2.5,
+                    color: pawOutline,
+                  ),
+                )
+              : const Icon(Icons.shuffle_rounded),
+        ),
+      ],
+    ),
+  );
+}
diff --git a/lib/ui/search_page.dart b/lib/ui/search_page.dart
index 2b2373a..b0786be 100644
--- a/lib/ui/search_page.dart
+++ b/lib/ui/search_page.dart
@@ -7,10 +7,12 @@ import '../core/models.dart';
 import 'app_scope.dart';
 import 'creator_page.dart';
 import 'post_card.dart';
+import 'tag_page.dart';
 import 'theme.dart';
 import 'widgets.dart';
 
-/// Finds artists by name and posts by text.
+/// Finds artists by name, posts by text, and tags (the site's popular tags
+/// filtered on the device, or any tag typed in).
 ///
 /// Artist search filters Pawchive's full creator list on the device; the
 /// list (~16 MB) is downloaded the first time this page needs it per
@@ -24,7 +26,7 @@ class SearchPage extends StatefulWidget {
 
 class _SearchPageState extends State<SearchPage>
     with SingleTickerProviderStateMixin {
-  late final TabController _tabs = TabController(length: 2, vsync: this);
+  late final TabController _tabs = TabController(length: 3, vsync: this);
   final _field = TextEditingController();
   Timer? _debounce;
   String _query = '';
@@ -103,6 +105,7 @@ class _SearchPageState extends State<SearchPage>
         tabs: const [
           Tab(text: 'Artists'),
           Tab(text: 'Posts'),
+          Tab(text: 'Tags'),
         ],
       ),
     ),
@@ -125,6 +128,7 @@ class _SearchPageState extends State<SearchPage>
                   title: 'No posts match "$_query"',
                 ),
               ),
+        _TagResults(query: _query),
       ],
     ),
   );
@@ -217,3 +221,119 @@ class _ArtistResults extends StatelessWidget {
     );
   }
 }
+
+/// The site's popular tags (loaded when this tab first opens), filtered by
+/// the query, under a shortcut to the posts with exactly the typed tag.
+class _TagResults extends StatefulWidget {
+  const _TagResults({required this.query});
+
+  final String query;
+
+  @override
+  State<_TagResults> createState() => _TagResultsState();
+}
+
+class _TagResultsState extends State<_TagResults>
+    with AutomaticKeepAliveClientMixin {
+  late Future<List<CreatorTag>> _tags = AppScope.read(context).popularTags();
+
+  @override
+  bool get wantKeepAlive => true;
+
+  String get _tag {
+    final query = widget.query.trim();
+    return query.startsWith('#') ? query.substring(1).trim() : query;
+  }
+
+  List<CreatorTag> _match(List<CreatorTag> all) {
+    final q = _tag.toLowerCase();
+    if (q.isEmpty) return all;
+    final starts = <CreatorTag>[];
+    final contains = <CreatorTag>[];
+    for (final tag in all) {
+      final name = tag.tag.toLowerCase();
+      if (name.startsWith(q)) {
+        starts.add(tag);
+      } else if (name.contains(q)) {
+        contains.add(tag);
+      }
+    }
+    // Popularity order within each group, as the site lists them.
+    return [...starts, ...contains];
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    super.build(context);
+    final tag = _tag;
+    return FutureBuilder<List<CreatorTag>>(
+      future: _tags,
+      builder: (context, snapshot) {
+        final matches = snapshot.hasData
+            ? _match(snapshot.data!)
+            : const <CreatorTag>[];
+        final header = <Widget>[
+          if (tag.isNotEmpty)
+            ListTile(
+              contentPadding: const EdgeInsets.fromLTRB(16, 6, 16, 6),
+              leading: const CircleAvatar(
+                backgroundColor: pawPink,
+                foregroundColor: pawOutline,
+                child: Icon(Icons.tag_rounded),
+              ),
+              title: Text(
+                'Posts tagged #$tag',
+                style: const TextStyle(fontWeight: FontWeight.w700),
+              ),
+              subtitle: Text(
+                'From every artist',
+                style: TextStyle(color: ink(.5)),
+              ),
+              trailing: const Icon(Icons.chevron_right_rounded),
+              onTap: () => openTag(context, tag),
+            ),
+          if (snapshot.hasError)
+            StatusView(
+              icon: Icons.cloud_off_rounded,
+              title: 'Could not load popular tags',
+              body: '${snapshot.error}',
+              action: 'Try again',
+              onAction: () =>
+                  setState(() => _tags = AppScope.read(context).popularTags()),
+            )
+          else if (!snapshot.hasData)
+            const Padding(
+              padding: EdgeInsets.all(32),
+              child: Center(child: CircularProgressIndicator()),
+            )
+          else if (matches.isNotEmpty)
+            SectionLabel(
+              tag.isEmpty ? 'Popular tags' : 'Popular tags like this',
+            )
+          else if (tag.isEmpty)
+            const StatusView(icon: Icons.tag_rounded, title: 'No tags'),
+        ];
+        return BackToTop(
+          child: ListView.builder(
+            padding: const EdgeInsets.only(bottom: 96),
+            itemCount: header.length + matches.length,
+            itemBuilder: (context, index) {
+              if (index < header.length) return header[index];
+              final item = matches[index - header.length];
+              return ListTile(
+                contentPadding: const EdgeInsets.symmetric(horizontal: 16),
+                leading: Icon(Icons.tag_rounded, color: ink(.5)),
+                title: Text(item.tag),
+                trailing: Text(
+                  '${compactCount(item.postCount)} posts',
+                  style: TextStyle(color: ink(.5), fontSize: 13),
+                ),
+                onTap: () => openTag(context, item.tag),
+              );
+            },
+          ),
+        );
+      },
+    );
+  }
+}
diff --git a/lib/ui/tag_page.dart b/lib/ui/tag_page.dart
new file mode 100644
index 0000000..e03ae5d
--- /dev/null
+++ b/lib/ui/tag_page.dart
@@ -0,0 +1,71 @@
+import 'package:flutter/material.dart';
+
+import '../core/config.dart';
+import '../core/feeds.dart';
+import 'app_scope.dart';
+import 'post_card.dart';
+import 'widgets.dart';
+
+/// Posts with a tag from every artist, newest first.
+class TagPostsPage extends StatefulWidget {
+  const TagPostsPage({super.key, required this.tag});
+
+  final String tag;
+
+  @override
+  State<TagPostsPage> createState() => _TagPostsPageState();
+}
+
+class _TagPostsPageState extends State<TagPostsPage> {
+  late final OffsetFeed _posts = OffsetFeed(
+    (offset) =>
+        AppScope.read(context).api.taggedPosts(widget.tag, offset: offset),
+  );
+
+  @override
+  void dispose() {
+    _posts.dispose();
+    super.dispose();
+  }
+
+  String get _url =>
+      '$siteUrl/posts?tag=${Uri.encodeQueryComponent(widget.tag)}';
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+    appBar: AppBar(
+      title: Text(
+        '#${widget.tag}',
+        style: const TextStyle(fontWeight: FontWeight.w700),
+      ),
+      actions: [
+        PopupMenuButton<VoidCallback>(
+          onSelected: (action) => action(),
+          itemBuilder: (_) => [
+            PopupMenuItem(
+              value: () => copyLink(context, _url),
+              child: const Text('Copy link'),
+            ),
+            PopupMenuItem(
+              value: () => openExternal(_url),
+              child: const Text('Open on Pawchive'),
+            ),
+          ],
+        ),
+      ],
+    ),
+    body: FeedView(
+      feed: _posts,
+      itemBuilder: (context, post) => PostCard(post),
+      empty: StatusView(
+        icon: Icons.tag_rounded,
+        title: 'No posts tagged #${widget.tag}',
+        body: 'Tags match exactly; try another spelling.',
+      ),
+    ),
+  );
+}
+
+void openTag(BuildContext context, String tag) =>
+    Navigator.of(context)
+        .push(MaterialPageRoute<void>(builder: (_) => TagPostsPage(tag: tag)));
diff --git a/lib/ui/widgets.dart b/lib/ui/widgets.dart
index f24846e..890d711 100644
--- a/lib/ui/widgets.dart
+++ b/lib/ui/widgets.dart
@@ -171,18 +171,122 @@ void scrollNestedToTop(NestedScrollViewState? nested) {
   if (nested == null) return;
   final inner = nested.innerController;
   if (inner.hasClients) {
-    final position = inner.positions.reduce(
-      (a, b) => a.pixels >= b.pixels ? a : b,
+    _jumpNearTop(
+      inner.positions.reduce((a, b) => a.pixels >= b.pixels ? a : b),
     );
-    final near = position.viewportDimension * 1.5;
-    if (position.pixels > near) position.jumpTo(near);
   }
   final outer = nested.outerController;
   if (!outer.hasClients) return;
-  outer.animateTo(
-    0,
-    duration: const Duration(milliseconds: 380),
-    curve: Curves.easeOutCubic,
+  outer.animateTo(0, duration: _toTop, curve: Curves.easeOutCubic);
+}
+
+/// [scrollNestedToTop] for a plain scroll view.
+void scrollToTop(ScrollPosition position) {
+  if (!position.hasPixels) return;
+  _jumpNearTop(position);
+  position.animateTo(0, duration: _toTop, curve: Curves.easeOutCubic);
+}
+
+const _toTop = Duration(milliseconds: 380);
+
+void _jumpNearTop(ScrollPosition position) {
+  final near = position.viewportDimension * 1.5;
+  if (position.pixels > near) position.jumpTo(near);
+}
+
+/// An arrow over a vertical scroll view that shows once it's a couple of
+/// screens down and takes it back to the top (header included inside a
+/// [NestedScrollView]).
+class BackToTop extends StatefulWidget {
+  const BackToTop({super.key, required this.child});
+
+  final Widget child;
+
+  @override
+  State<BackToTop> createState() => _BackToTopState();
+}
+
+class _BackToTopState extends State<BackToTop> {
+  final _shown = ValueNotifier(false);
+  ScrollPosition? _position;
+
+  @override
+  void dispose() {
+    _shown.dispose();
+    super.dispose();
+  }
+
+  bool _onScroll(ScrollNotification notification) {
+    final metrics = notification.metrics;
+    if (notification.depth != 0 || metrics.axis != Axis.vertical) {
+      return false;
+    }
+    _position = notification.context
+        ?.findAncestorStateOfType<ScrollableState>()
+        ?.position;
+    _shown.value = metrics.pixels > metrics.viewportDimension * 2;
+    return false;
+  }
+
+  void _up() {
+    _shown.value = false;
+    final nested = context.findAncestorStateOfType<NestedScrollViewState>();
+    if (nested != null) return scrollNestedToTop(nested);
+    final position = _position;
+    if (position != null) scrollToTop(position);
+  }
+
+  @override
+  Widget build(BuildContext context) => Stack(
+    children: [
+      NotificationListener<ScrollNotification>(
+        onNotification: _onScroll,
+        child: widget.child,
+      ),
+      Positioned(
+        left: 0,
+        right: 0,
+        bottom: MediaQuery.paddingOf(context).bottom + 16,
+        child: Center(
+          child: ValueListenableBuilder<bool>(
+            valueListenable: _shown,
+            builder: (context, shown, child) => IgnorePointer(
+              ignoring: !shown,
+              child: AnimatedScale(
+                scale: shown ? 1 : .4,
+                duration: const Duration(milliseconds: 200),
+                curve: Curves.easeOutBack,
+                child: AnimatedOpacity(
+                  opacity: shown ? 1 : 0,
+                  duration: const Duration(milliseconds: 160),
+                  child: child,
+                ),
+              ),
+            ),
+            child: Material(
+              color: pawPink,
+              shape: const CircleBorder(),
+              elevation: 4,
+              child: InkWell(
+                customBorder: const CircleBorder(),
+                onTap: _up,
+                child: const Tooltip(
+                  message: 'Back to top',
+                  child: Padding(
+                    padding: EdgeInsets.all(11),
+                    child: Icon(
+                      Icons.arrow_upward_rounded,
+                      color: pawOutline,
+                      size: 22,
+                    ),
+                  ),
+                ),
+              ),
+            ),
+          ),
+        ),
+      ),
+    ],
   );
 }
 
@@ -329,26 +433,28 @@ class _FeedViewState extends State<FeedView> {
     listenable: widget.feed,
     builder: (context, _) {
       final feed = widget.feed;
-      return RefreshIndicator(
-        onRefresh: feed.refresh,
-        edgeOffset: widget.overlapHandle == null ? 0 : 100,
-        child: NotificationListener<ScrollNotification>(
-          onNotification: _onScroll,
-          child: CustomScrollView(
-            key: PageStorageKey(feed),
-            physics: const AlwaysScrollableScrollPhysics(),
-            slivers: [
-              if (widget.overlapHandle != null)
-                SliverOverlapInjector(handle: widget.overlapHandle!),
-              ?widget.header,
-              SliverList.separated(
-                itemCount: feed.posts.length,
-                itemBuilder: (context, index) =>
-                    widget.itemBuilder(context, feed.posts[index]),
-                separatorBuilder: (_, _) => const Divider(),
-              ),
-              SliverToBoxAdapter(child: _footer(feed)),
-            ],
+      return BackToTop(
+        child: RefreshIndicator(
+          onRefresh: feed.refresh,
+          edgeOffset: widget.overlapHandle == null ? 0 : 100,
+          child: NotificationListener<ScrollNotification>(
+            onNotification: _onScroll,
+            child: CustomScrollView(
+              key: PageStorageKey(feed),
+              physics: const AlwaysScrollableScrollPhysics(),
+              slivers: [
+                if (widget.overlapHandle != null)
+                  SliverOverlapInjector(handle: widget.overlapHandle!),
+                ?widget.header,
+                SliverList.separated(
+                  itemCount: feed.posts.length,
+                  itemBuilder: (context, index) =>
+                      widget.itemBuilder(context, feed.posts[index]),
+                  separatorBuilder: (_, _) => const Divider(),
+                ),
+                SliverToBoxAdapter(child: _footer(feed)),
+              ],
+            ),
           ),
         ),
       );
diff --git a/test/back_to_top_test.dart b/test/back_to_top_test.dart
new file mode 100644
index 0000000..cdce822
--- /dev/null
+++ b/test/back_to_top_test.dart
@@ -0,0 +1,42 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pawress/ui/widgets.dart';
+
+void main() {
+  testWidgets('BackToTop shows past two screens and scrolls up', (
+    tester,
+  ) async {
+    final controller = ScrollController();
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          body: BackToTop(
+            child: ListView.builder(
+              controller: controller,
+              itemCount: 500,
+              itemBuilder: (_, index) =>
+                  SizedBox(height: 100, child: Text('row $index')),
+            ),
+          ),
+        ),
+      ),
+    );
+    final arrow = find.byIcon(Icons.arrow_upward_rounded);
+    double opacity() => tester
+        .widget<AnimatedOpacity>(
+          find.ancestor(of: arrow, matching: find.byType(AnimatedOpacity)),
+        )
+        .opacity;
+    expect(opacity(), 0);
+
+    await tester.drag(find.byType(ListView), const Offset(0, -3000));
+    await tester.pumpAndSettle();
+    expect(controller.offset, greaterThan(2000));
+    expect(opacity(), 1);
+
+    await tester.tap(arrow);
+    await tester.pumpAndSettle();
+    expect(controller.offset, 0);
+    expect(opacity(), 0);
+  });
+}
diff --git a/test/explore_test.dart b/test/explore_test.dart
new file mode 100644
index 0000000..98a85cf
--- /dev/null
+++ b/test/explore_test.dart
@@ -0,0 +1,203 @@
+import 'dart:convert';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:http/http.dart' as http;
+import 'package:http/testing.dart';
+import 'package:pawress/core/api.dart';
+import 'package:pawress/core/file_hash.dart';
+import 'package:pawress/core/models.dart';
+import 'package:pawress/core/store.dart';
+
+// Trimmed from the live /posts/tags and /posts?tag= pages.
+const _tagsPage = '''
+<section id="tag-container">
+    <article>
+      <a href="/posts?tag=nsfw">
+        <span>nsfw</span>
+        <span>532728</span>
+      </a>
+    </article>
+    <article>
+      <a href="/posts?tag=Tom%20%26%20Jerry">
+        <span>Tom &amp; Jerry</span>
+        <span>12</span>
+      </a>
+    </article>
+</section>
+''';
+
+const _taggedPage = '''
+<div class="card-list__items">
+  <article
+    class="post-card post-card--preview"
+    data-id="174253068"
+    data-service="patreon"
+    data-user="129539710"
+  >
+    <a href="/patreon/user/129539710/post/174253068">
+      <header class="post-card__header">
+            Red fox
+      </header>
+        <div class="post-card__image-container">
+            <img
+              class="post-card__image"
+              src="https://img.pawchive.pw/thumbnail/data/1a/bd/1abd.jpg"
+              alt="Red fox"
+              loading="lazy"
+            >
+          </div>
+      <footer class="post-card__footer">
+              <time class="timestamp " datetime="2026-11-03 10:04:29">
+  </time>
+      </footer>
+    </a>
+  </article>
+</div>
+''';
+
+void main() {
+  test('parseTagPage reads tags and counts in order', () {
+    final tags = parseTagPage(_tagsPage);
+    expect(tags.map((t) => t.tag), ['nsfw', 'Tom & Jerry']);
+    expect(tags.map((t) => t.postCount), [532728, 12]);
+  });
+
+  test('taggedPosts reads the tag page and pages with o', () async {
+    final requested = <Uri>[];
+    final api = PawchiveApi(
+      client: MockClient((request) async {
+        requested.add(request.url);
+        return http.Response(_taggedPage, 200);
+      }),
+    );
+    final posts = await api.taggedPosts('red fox', offset: 50);
+    expect(requested.single.path, '/posts');
+    expect(requested.single.queryParameters, {'tag': 'red fox', 'o': '50'});
+    expect(posts.single.id, '174253068');
+    expect(posts.single.title, 'Red fox');
+    // Only the thumbnail is known, so the viewer fetches the post.
+    expect(posts.single.file!.previewOnly, isTrue);
+  });
+
+  test('PawchiveLink reads post and artist links', () {
+    final post = PawchiveLink.tryParse(
+      'https://pawchive.pw/patreon/user/17722258/post/56165801',
+    )!;
+    expect(
+      (post.service, post.user, post.post),
+      ('patreon', '17722258', '56165801'),
+    );
+    final artist = PawchiveLink.tryParse('/fanbox/user/184422192')!;
+    expect(
+      (artist.service, artist.user, artist.post),
+      ('fanbox', '184422192', null),
+    );
+    expect(PawchiveLink.tryParse('https://pawchive.pw/'), isNull);
+  });
+
+  test(
+    'randomPost and randomCreator read the redirect without following',
+    () async {
+      final api = PawchiveApi(
+        client: MockClient((request) async {
+          expect(request.followRedirects, isFalse);
+          final location = request.url.path == '/posts/random'
+              ? 'https://pawchive.pw/patreon/user/1/post/2'
+              : 'https://pawchive.pw/fanbox/user/3';
+          return http.Response('', 302, headers: {'location': location});
+        }),
+      );
+      final post = await api.randomPost();
+      expect((post.service, post.user, post.post), ('patreon', '1', '2'));
+      final creator = await api.randomCreator();
+      expect(creator.key, 'fanbox/3');
+    },
+  );
+
+  test('random without a location is an error', () async {
+    final api = PawchiveApi(
+      client: MockClient((_) async => http.Response('', 200)),
+    );
+    expect(api.randomPost(), throwsA(isA<ApiException>()));
+  });
+
+  test('searchHash reads posts and Discord matches, and 404 as none', () async {
+    const hash =
+        '925a6e2842e2cc617e4dde55ebd35b8acba95b2613acf0a541ccbc68ae58b594';
+    final api = PawchiveApi(
+      client: MockClient((request) async {
+        if (!request.url.path.endsWith(hash)) return http.Response('{}', 404);
+        return http.Response(
+          jsonEncode({
+            'hash': hash,
+            'posts': [
+              {
+                'id': '174298665',
+                'user': '397567',
+                'service': 'patreon',
+                'title': 'The Mom Next Door',
+                'content': '<p>If you live',
+                'published': '2026-11-03T19:26:15',
+                'file': {
+                  'name': 'a.png',
+                  'node': 2,
+                  'path': '/92/5a/$hash.png',
+                },
+                'attachments': [],
+              },
+            ],
+            'discord_posts': [
+              {'id': '1'},
+            ],
+          }),
+          200,
+        );
+      }),
+    );
+    final found = (await api.searchHash(hash.toUpperCase()))!;
+    expect(found.hash, hash);
+    expect(found.posts.single.id, '174298665');
+    expect(found.posts.single.files.single.fullUrl, isNotNull);
+    expect(found.discordCount, 1);
+    expect(await api.searchHash('0' * 64), isNull);
+  });
+
+  test('HashLookup reads null Discord posts as none', () {
+    final lookup = HashLookup.fromJson({
+      'hash': 'ab',
+      'posts': [],
+      'discord_posts': null,
+    });
+    expect(lookup.discordCount, 0);
+    expect(lookup.posts, isEmpty);
+  });
+
+  test('sha256Hex hashes across chunks and reports progress', () async {
+    final read = <int>[];
+    final hash = await sha256Hex(
+      Stream.fromIterable([utf8.encode('a'), utf8.encode('bc')]),
+      onProgress: read.add,
+    );
+    expect(
+      hash,
+      'ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad',
+    );
+    expect(read, [1, 3]);
+    expect(isSha256(hash), isTrue);
+    expect(isSha256(hash.toUpperCase()), isTrue);
+    expect(isSha256('${hash}0'), isFalse);
+    expect(isSha256('g' * 64), isFalse);
+  });
+
+  test('AppSettings keeps the Random choice', () {
+    expect(const AppSettings().randomKind, isNull);
+    final settings = AppSettings.fromJson(
+      const AppSettings().copyWith(randomKind: RandomKind.artist).toJson(),
+    );
+    expect(settings.randomKind, RandomKind.artist);
+    expect(
+      settings.copyWith(checkUpdates: false).randomKind,
+      RandomKind.artist,
+    );
+  });
+}