Awesome Second Brain

A curated, neutral list of tools, methods, and resources for building a second brain.

A second brain is a personal system for capturing what you learn and finding it again when you need it. This list gathers the apps, open-source projects, methods, books, creators, and communities people use to build one, from note-taking tools and knowledge bases to the new wave of personal AI that can answer from your own material.

It is community-maintained and does not rank or endorse any product. Every entry links to an official site or source repository. Maintained by the team behind Mindola. Found something missing or out of date? Contributions are welcome.

Tags: oss open source, selfhost self-hostable, local local-first, free free tier, paid paid only, ai AI-native, mobile mobile apps.

Contents

• Personal AI & Digital Twins
• AI Over Your Own Notes
• Note-Taking & PKM Apps
• Open-Source & Self-Hosted
• Capture, Read-It-Later & Highlights
• Methods & Frameworks
• Books & Courses
• Creators, Newsletters & Podcasts
• Communities
• Ecosystem & Publishing

Personal AI & Digital Twins

Tools that build a chattable AI version of a person from their content, voice, or knowledge.

• AI Twin by OpenHome - iOS app that clones your voice and personality from a short setup so you can talk with an AI version of yourself free ai mobile.
• Character.ai - Lets anyone create and chat with custom AI characters, including personas modeled on themselves, on web and mobile free ai mobile.
• Coachvox AI - Creates an AI version of a coach or entrepreneur that answers client questions in their style and captures leads paid ai.
• Delphi - Turns a creator's books, talks, and posts into an interactive AI their audience can chat with anytime ai.
• HeyGen - Creates a video avatar clone of a person, including a real-time interactive avatar others can talk to free ai mobile.
• Kin - Private, local-first personal AI with on-device memory offering journaling and a board of AI advisors on mobile local free ai mobile.
• Me.bot - Personal AI companion that turns notes, memories, and chats into an organized, queryable second brain free ai mobile.
• MindBank AI - Creates a digital twin from a person's voice and knowledge that can answer questions and coach in 40+ languages free ai.
• Mindola - Turns a professional's site, PDFs, and videos into a source-grounded AI lens visitors can chat with free ai.
• MyClone - Creates an AI clone that answers in a user's voice and captures leads, embeddable on sites or shared as a widget ai.
• Personal.ai - Builds a private personal AI with long-term memory that answers in the user's own voice from their messages and notes ai mobile.
• Second Me - Open-source, locally trained and hosted AI self built from your data using hierarchical memory modeling oss selfhost local free ai.
• Sensay - Creates AI replicas trained on a person's files, sites, and videos that others can message across web and social channels free ai.
• Tavus - Developer platform for building real-time conversational video digital-twin replicas through an API ai.
• Twin Protocol - Uses AI and Blockchain to let people build digital twins of their expertise that others can query and that earn tokens ai.
• Twineo - Mobile app that trains a digital twin on your opinions and interests to answer surveys on your behalf for rewards free ai mobile.
• Viven - Builds a digital twin of each employee from internal documents and chats so coworkers can query them when unavailable paid ai.

AI Over Your Own Notes

Assistants that answer questions and search over your own documents, notes, and files.

• Amurex - Open-source AI companion that transcribes meetings and searches across your connected knowledge sources (source) oss selfhost free ai.
• AnythingLLM - Desktop and Docker app for RAG chat and agents over your documents, using local or cloud models (source) oss selfhost local free ai.
• Cheshire Cat AI - Open-source framework for building AI assistants with long-term memory and retrieval over ingested documents (source) oss selfhost free ai.
• Elephas - Apple-only AI assistant that builds a searchable brain from your local files and notes for writing and Q&A local paid ai mobile.
• Google NotebookLM - Google research tool that grounds chat, summaries, and audio overviews in the sources you upload free ai mobile.
• GPT4All - Desktop app to run local LLMs offline, with a LocalDocs feature to chat privately with your own files (source) oss local free ai.
• Humata - Web app to upload documents and ask questions across them, with answers cited back to your files free ai.
• Khoj - Self-hostable AI assistant that answers questions from your notes, documents, and the web using local or cloud models (source) oss selfhost local free ai mobile.
• Mem - AI note app that captures, auto-organizes, and resurfaces notes, and answers questions across them via chat paid ai mobile.
• Msty - Local-first desktop app to run online and offline models with a Knowledge Stack for chatting with your files local free ai.
• Notion AI - AI built into Notion that answers questions and writes using content from your workspace and connected apps paid ai mobile.
• Onyx - Open-source AI chat and search that connects to your documents and apps through many data connectors (source) oss selfhost free ai.
• Open WebUI - Self-hosted AI interface for Ollama and OpenAI-compatible models with built-in RAG over your documents (source) oss selfhost local free ai.
• PrivateGPT - Open-source API layer for privately chatting with your documents using local models, with no data leaving your machine oss selfhost local free ai.
• Quivr - Open-source RAG framework for building assistants that answer questions over your own files and data oss selfhost free ai.
• Saga - Workspace for notes, docs, and tasks with a built-in AI assistant that can answer across your pages free ai.
• Sider - Browser AI sidebar that chats with the current page, your uploaded PDFs, and saved content across many models free ai mobile.

Note-Taking & PKM Apps

General note-taking and personal knowledge management applications.

• Amplenote - Note-taking and task app linking notes to to-dos and a calendar, with published notes and encryption free mobile.
• Apple Notes - Apple's built-in note-taking app for iPhone, iPad, and Mac with iCloud sync, sketches, and folders free mobile.
• Bear - Markdown note-taking app for Apple devices with tagging and cross-device sync in its paid plan free mobile.
• Capacities - Object-based note-taking app that organizes content into typed objects with links, daily notes, and AI free ai mobile.
• Craft - Document and note editor with structured blocks, daily notes, collaboration, and AI assistance free ai mobile.
• Evernote - Note-taking and organization app with web clipping, document search, tasks, and cross-device sync free ai mobile.
• Heptabase - Visual whiteboard note app using an infinite canvas with reusable cards, links, PDF annotation, and AI local paid ai mobile.
• Ideaflow - Note-taking app focused on fast idea capture through text and voice, with AI-assisted organization ai mobile.
• Microsoft OneNote - Microsoft's free-form digital notebook for typed, handwritten, and clipped notes, synced across devices free mobile.
• Napkin - iPhone app for capturing ideas and quotes, with AI curation that resurfaces and connects them ai mobile.
• Notion - Block-based workspace combining notes, documents, databases, and AI in one editor free ai mobile.
• Nototo - Spatial note-taking app that arranges notes on a map-like canvas to build a visual memory palace.
• Obsidian - Markdown-based note-taking app that stores files locally and links them into a graph, with community plugins local free mobile.
• Reflect - End-to-end encrypted networked note-taking app with backlinks, calendar sync, voice transcription, and AI paid ai mobile.
• RemNote - Note-taking app with built-in spaced-repetition flashcards, PDF annotation, and AI card generation free ai mobile.
• Roam Research - Note-taking tool built on a graph database with bidirectional links and daily notes for networked thought paid mobile.
• Supernotes - Note-taking app built around linked notecards with real-time collaboration, sharing, and AI features free ai mobile.
• Tana - Outliner that structures notes with supertags and fields, plus AI features and voice capture free ai mobile.

Open-Source & Self-Hosted

Open-source and self-hostable knowledge bases, note apps, and wikis.

• AFFiNE - Open-source workspace merging documents, whiteboards, and databases with local-first storage and self-hosting (source) oss selfhost local free ai mobile.
• Anytype - Local-first, end-to-end encrypted workspace for notes, tasks, and databases with peer-to-peer sync (source) oss selfhost local free mobile.
• AppFlowy - Open-source Notion alternative combining documents, databases, and AI with local-first storage and self-hosting (source) oss selfhost local free ai mobile.
• Athens Research - Open-source, local-first knowledge graph inspired by Roam Research; the project is no longer maintained oss local free.
• Blinko - Open-source, self-hostable AI note-taking app for quick capture with retrieval-augmented natural-language search (source) oss selfhost free ai mobile.
• BookStack - Open-source, self-hostable wiki and documentation platform organizing content into shelves, books, and pages (source) oss selfhost free.
• Dendron - Open-source, Markdown-based note-taking extension for VS Code organized around hierarchical note schemas (source) oss local free.
• Docmost - Open-source, self-hostable collaborative wiki and documentation platform with real-time editing and spaces (source) oss selfhost free.
• Foam - Open-source personal knowledge management extension for VS Code using Markdown, wikilinks, and graph views (source) oss local free.
• Joplin - Open-source, offline-first note and to-do app with Markdown and end-to-end encrypted sync across desktop and mobile (source) oss selfhost local free mobile.
• Logseq - Open-source, local-first outliner for notes and knowledge graphs using Markdown or Org-mode with backlinks (source) oss local free mobile.
• Memos - Lightweight, self-hosted note-taking service for quick Markdown capture with REST and gRPC APIs (source) oss selfhost free.
• Notesnook - Open-source, end-to-end encrypted note-taking app with a self-hostable sync server and cross-platform clients (source) oss selfhost free mobile.
• Outline - Open-source, self-hostable team knowledge base and wiki with real-time collaboration and Markdown support (source) oss selfhost free.
• SilverBullet - Open-source, self-hostable Markdown knowledge base that runs as an offline-capable PWA with built-in scripting (source) oss selfhost local free.
• SiYuan - Local-first, self-hostable knowledge base with block-level references, bidirectional links, and Markdown editing (source) oss selfhost local free mobile.
• Standard Notes - Open-source, end-to-end encrypted notes app with a self-hostable sync server and cross-platform apps (source) oss selfhost free mobile.
• Trilium Notes - Open-source hierarchical note-taking app for large personal knowledge bases, self-hostable via the web (source) oss selfhost local free.
• Wiki.js - Open-source, self-hostable wiki platform built on Node.js with Markdown, WYSIWYG, and multiple storage backends (source) oss selfhost free.
• Zettlr - Open-source Markdown editor for academic and long-form writing with citations, Zotero, and Pandoc export (source) oss local free.

Capture, Read-It-Later & Highlights

Tools for saving articles, bookmarks, and highlights and resurfacing them later.

• Anybox - Native bookmark and read-later manager for Apple devices with iCloud sync and local storage local paid mobile.
• Fabric - AI workspace and file explorer that stores notes, files, and web clips and links them by meaning free ai mobile.
• Glasp - Social highlighter for web pages, PDFs, and YouTube that saves highlights and follows other people's highlights free ai.
• Hypothes.is - Open-source web and PDF annotation layer for highlighting, note-taking, and shared or private discussion (source) oss selfhost free.
• Instapaper - Read-it-later service that saves web articles into a clean reading view with highlights and cross-device sync free mobile.
• Karakeep - Open-source, self-hostable bookmark app (formerly Hoarder) with AI-based tagging and full-text search (source) oss selfhost free ai mobile.
• Liner - AI highlighter and research assistant for web pages, PDFs, and YouTube, paired with an AI search engine free ai mobile.
• linkding - Self-hosted bookmark manager built with Django, with tags, browser extensions, and a REST API oss selfhost free.
• Linkwarden - Open-source bookmark manager that collects, annotates, and archives web pages as snapshots and PDFs (source) oss selfhost free ai mobile.
• Matter - Read-later app for articles, newsletters, and feeds with text-to-speech and highlight export to note apps free ai mobile.
• MyMind - Private visual bookmarking app that uses AI to auto-tag and organize saved links, images, notes, and articles paid ai mobile.
• Notion Web Clipper - Notion's official browser extension for saving web pages into a Notion workspace free.
• Omnivore - Open-source read-it-later and highlighting app; the hosted service closed in 2024 and the code is self-hostable oss selfhost.
• Pinboard - Minimal, privacy-focused bookmarking service with tags and an optional full-text archiving add-on paid.
• Raindrop.io - Bookmark manager that saves links, articles, and media into taggable collections with search and archived copies free mobile.
• Readwise - Aggregates highlights from Kindle, articles, and podcasts and resurfaces them with spaced repetition paid mobile.
• Readwise Reader - Read-it-later app for articles, newsletters, RSS, PDFs, EPUBs, and videos, with highlighting and AI features paid ai mobile.
• Recall - AI knowledge base that saves and summarizes articles, videos, podcasts, and PDFs and links them in a graph free ai mobile.
• Save to Notion - Third-party browser extension that saves web pages and highlights into Notion databases with mapped properties free.
• Snipd - AI podcast player that captures highlight clips with transcript and summary and exports notes to note apps free ai mobile.
• Wallabag - Open-source, self-hostable read-it-later app that saves web pages into a clean reading view with tags (source) oss selfhost free mobile.
• Weava - Research highlighter for web pages and PDFs with color-coded highlights, folders, annotations, and citations free.
• Web Highlights - Browser extension for highlighting and annotating web pages and PDFs with notes, tags, and AI summaries free ai.

Methods & Frameworks

Note-taking and knowledge-management methods, systems, and frameworks.

• Antinet Zettelkasten - Scott Scheper's analog, paper-based interpretation of Luhmann's Zettelkasten using numbered index cards.
• Building a Second Brain (BASB) - Tiago Forte's method for capturing, organizing, and reusing knowledge across digital notes, built on the CODE steps.
• Bullet Journal Method - Ryder Carroll's analog method combining rapid logging, collections, and migration to track tasks, events, and notes.
• Cornell Note-Taking System - Note-taking format from Cornell University that splits the page into cues, notes, and a summary for review.
• Digital Garden - Maggie Appleton's essay on digital gardening, publishing evolving, interlinked personal notes on the web.
• Evergreen Notes - Andy Matuschak's practice of writing atomic, concept-oriented notes that are developed and linked over time.
• Getting Things Done (GTD) - David Allen's productivity method for capturing tasks into trusted lists organized by context and next action.
• Intermediate Packets - Tiago Forte's concept of breaking work into reusable chunks of notes and drafts that can be saved and recombined.
• Johnny.Decimal - Numbering system that assigns unique IDs to files and notes using areas and categories so items are quick to locate.
• Linking Your Thinking (LYT) - Nick Milo's note-taking framework centered on Maps of Content, index notes that link and surface related ideas.
• PARA Method - Tiago Forte's system that sorts information into Projects, Areas, Resources, and Archives by actionability.
• Progressive Summarization - Tiago Forte's technique of layering highlights and summaries so key ideas in a note stay easy to find later.
• Zettelkasten - Note-taking method built on Niklas Luhmann's slip-box, where atomic notes are densely linked into a web of ideas.

Books & Courses

Books and courses about note-taking, PKM, and second-brain systems.

• A System for Writing - Bob Doto's Zettelkasten primer on note-making and turning linked notes into finished writing paid.
• Ali Abdaal Productivity Masterclass - Ali Abdaal's Skillshare course on productivity principles, tools, and note-taking workflows paid.
• Building a Second Brain - Tiago Forte's book introducing the CODE method for capturing and organizing notes into a knowledge system paid.
• Building a Second Brain Foundation - Cohort and self-paced online course teaching Tiago Forte's Building a Second Brain method paid.
• Digital Zettelkasten - David Kadavy's short book on adapting the Zettelkasten note-taking method to digital tools paid.
• How to Take Smart Notes - Sonke Ahrens's book presenting a Zettelkasten-based note-taking workflow for writing, learning, and research paid.
• Linking Your Thinking Workshop - Nick Milo's cohort workshop on linked note-taking and building a personal knowledge system paid.
• Notion Fundamentals - Thomas Frank's free beginner course covering Notion pages, blocks, links, and databases free.
• Notion Life Design (PPV) - August Bradley's course on building a Notion life OS with the Pillars, Pipelines, Vaults framework paid.
• Notion Mastery - Marie Poulin's course on designing personal and business systems and workflows in Notion paid.
• The AI Second Brain - Tiago Forte's cohort course on applying AI tools to a personal knowledge management system paid ai.
• The Bullet Journal Method - Ryder Carroll's book on the analog Bullet Journal system for notes, tasks, and planning on paper paid.
• The PARA Method - Tiago Forte's book on organizing digital information into Projects, Areas, Resources, and Archives paid.

Creators, Newsletters & Podcasts

People, newsletters, podcasts, and channels covering PKM and tools for thought.

• Aidan Helfant - Aidan Helfant's YouTube channel and podcast interviewing people about their personal knowledge management systems.
• Ali Abdaal - Ali Abdaal's site, YouTube channel, and podcast on productivity, studying, and note-taking systems.
• Andy Matuschak - Researcher Andy Matuschak's site on tools for thought, evergreen notes, and spaced-repetition learning, with public notes.
• August Bradley (Year Zero) - August Bradley's YouTube channel and courses on the Notion PPV life operating system and knowledge management.
• Bryan Jenks - Bryan Jenks's site and YouTube channel on Obsidian, Zettelkasten, and personal knowledge management workflows.
• Chris Aldrich (BoffoSocko) - Chris Aldrich's site on commonplace books, Zettelkasten, note-taking history, and the IndieWeb.
• Curtis McHale - Curtis McHale's site and PKM Weekly newsletter reviewing note-taking tools, Obsidian, and knowledge workflows.
• Dann Berg - Dann Berg's site and newsletter with Obsidian tips and personal productivity workflows.
• Danny Hatcher - Danny Hatcher's YouTube channel and PKM podcast on Obsidian and personal knowledge management.
• Elizabeth Butler (Calmer Notes) - Elizabeth Butler's site and Calmer Notes courses on minimalist note-taking and personal knowledge management.
• Forte Labs (Tiago Forte) - Tiago Forte's site and courses on the Building a Second Brain and PARA note-taking methods, plus a blog and podcast.
• FromSergio - FromSergio's YouTube channel on Obsidian and personal knowledge management workflows.
• Nat Eliason - Nat Eliason's site, newsletter, and Roam course on note-taking and turning notes into published writing.
• Ness Labs (Anne-Laure Le Cunff) - Anne-Laure Le Cunff's site and weekly newsletter on neuroscience-based mindful productivity, learning, and thinking.
• Nicole van der Hoeven - Nicole van der Hoeven's site and YouTube channel on Obsidian and personal knowledge management.
• Obsidian Roundup (Eleanor Konik) - Eleanor Konik's Obsidian Roundup, a weekly newsletter of Obsidian news, tips, and community resources.
• Santi Younger - Santi Younger's site and YouTube channel on Obsidian, tools for thought, and building personal knowledge systems.
• Shu Omi - Shu Omi's site and YouTube channel on note-taking and second-brain workflows in Roam and Obsidian.
• The Informed Life (Jorge Arango) - Jorge Arango's The Informed Life, an interview podcast on how people organize information to get things done.
• Thomas Frank - Thomas Frank's YouTube channels and site on productivity, studying, and second-brain systems in Notion.
• Tool Finder (Francesco D'Alessio) - Francesco D'Alessio's Tool Finder site and Keep Productive channel reviewing note-taking and productivity apps.

Communities

Forums, subreddits, and chat servers for PKM tools and methods.

• Anytype Community - Official forum for Anytype users to share feedback, report bugs, and request features.
• Capacities Community - Community hub for Capacities linking its Discord server for users of the object-based note-taking app.
• DEVONtechnologies Community - Official Discourse forum for DEVONthink and other DEVONtechnologies apps, with team and user support.
• Heptabase Discord - Official Heptabase Discord server for product updates, support, and discussion of the visual note tool.
• Joplin Forum - Official Discourse forum for the open-source Joplin note-taking app, covering support and development.
• Logseq Discord - Official Logseq Discord server for real-time discussion, help, and workflow sharing.
• Logseq Forum - Official Discourse forum for Logseq users to ask questions, request features, and share workflows.
• Obsidian Forum - Official Discourse forum for Obsidian users covering help, plugins, feature requests, and PKM discussion.
• Obsidian Members Group (Discord) - Official Obsidian Discord server for real-time chat about the note-taking app and its plugins.
• PKM.social - Mastodon instance for people interested in personal knowledge management, note-taking, and related tools.
• r/Anytype - Reddit community for Anytype users discussing the local-first, privacy-focused knowledge app.
• r/logseq - Reddit community for Logseq users discussing the open-source outliner and knowledge-management app.
• r/Notion - Reddit community where Notion users share templates, workflows, and help with the all-in-one workspace.
• r/ObsidianMD - Reddit community for Obsidian users to share plugins, workflows, and questions about the note-taking app.
• r/PKMS - Reddit community for discussing personal knowledge management systems, methods, and tools across apps.
• r/RoamResearch - Reddit community for Roam Research users discussing networked note-taking and workflows.
• r/Zettelkasten - Reddit community focused on the Zettelkasten note-taking method and its use across various tools.
• Talk @ TiddlyWiki - Official Discourse forum for TiddlyWiki users covering help, plugins, and new releases.
• Tana Community - Community hub for Tana, linking its Slack workspace and user-created resources for the outliner app.
• Zettelkasten Forum - Discussion forum at zettelkasten.de covering the Zettelkasten method, note-taking theory, and software.
• Zotero Forums - Official support forum for the Zotero reference manager, staffed by developers and community members.

Ecosystem & Publishing

Plugins, publishing tools, and utilities that extend note-taking apps.

• Advanced Tables - Obsidian plugin for formatting, navigating, and editing Markdown tables with spreadsheet-style controls oss local free.
• Astro Digital Garden - Astro theme and toolset for publishing a digital garden from Markdown or Obsidian notes oss selfhost free.
• Calendar - Obsidian sidebar calendar for creating and navigating between daily and weekly notes oss local free.
• Copilot for Obsidian - AI assistant plugin for Obsidian offering chat, vault search, and commands across LLM providers oss local free ai.
• Dataview - Query language and live views that index Markdown notes and their metadata inside Obsidian oss local free.
• Excalidraw for Obsidian - Obsidian plugin for creating and embedding hand-drawn style sketches and diagrams in notes oss local free.
• Flowershow - Publishes Markdown and Obsidian vaults as websites, self-hosted or through a hosted service (source) oss selfhost free.
• Obsidian Digital Garden - Obsidian plugin that publishes selected notes as a self-hosted digital garden website (source) oss selfhost free.
• Obsidian Git - Plugin that version-controls an Obsidian vault with automatic Git commit, pull, and push oss local free.
• Obsidian Kanban - Obsidian plugin that creates Markdown-backed Kanban boards with draggable cards and lanes oss local free.
• Obsidian Publish - Obsidian's official hosted service for publishing selected vault notes as a linked website paid.
• Obsidian Tasks - Task management plugin for Obsidian with due dates, recurrence, and query-based task lists oss local free.
• Obsidian Web Clipper - Official Obsidian browser extension that saves web pages and highlights as Markdown notes oss local free.
• Omnisearch - Full-text search plugin for Obsidian with relevance ranking plus PDF and OCR indexing oss local free.
• Periodic Notes - Obsidian plugin for creating and managing daily, weekly, monthly, and yearly notes oss local free.
• Perlite - Self-hosted web viewer that publishes an Obsidian vault with graph view and backlinks oss selfhost free.
• Quartz - Static site generator that publishes Markdown notes and digital gardens with links and a graph view (source) oss selfhost free.
• QuickAdd - Obsidian plugin for quick capture, templates, and macro-based note automation oss local free.
• Smart Connections - Obsidian plugin that surfaces related notes and offers chat using local AI embeddings oss local free ai.
• Templater - Obsidian templating plugin that inserts variables, dates, and JavaScript output into notes oss local free.
• TiddlyWiki - Self-contained non-linear notebook that stores an entire personal wiki in a single HTML file (source) oss selfhost local free.

Contributing

Contributions are welcome. Read the contribution guidelines first, then open a pull request. Keep entries neutral, alphabetical, and verified.