PNG Metadata GUI

A fast, cross-platform desktop viewer for PNG text chunks (tEXt, zTXt, iTXt), built for browsing ComfyUI and Stable Diffusion metadata.

Open a folder and every image appears in a table with a sortable column for each pinned field (seed, steps, cfg, denoise, and so on). Select an image to browse its metadata as a tree where any value copies with a click. Search filters the folder to images whose metadata matches. This suits A/B testing, since a whole folder's settings show at once instead of one image at a time.

Written in Rust with egui. Single small binary, instant startup, no browser engine.

Features

• Folder table with thumbnails and a sortable column per pinned field
• Pin a key (cfg, matches every location), an exact path (prompt.183.inputs.cfg), or a node title ("Positive Prompt") on ComfyUI images. A title pin follows the node's _meta.title, so it keeps working across workflows whose node ids differ
• Rename any pin chip (right-click → Rename) to control its column header
• Repeated keys (generation vs upscale cfg) show every value, color-coded, with full paths in the tooltip
• Live search over keys, values, and dotted paths. The metadata tree prunes to matches and stays collapsible
• Find box that jumps to a field in the tree. Matching a node title opens the whole node, and Enter cycles through matches
• Collapsible JSON tree with expand/collapse all, copy buttons, and click-to-copy values
• A copy button beside every pinned value in the table, on by default for any pin named for a prompt or a seed. Right-click a pin chip to turn it on or off
• Click a thumbnail to open the image in its own window. Drag to pan, and the bottom bar holds zoom, fit, native size, and fullscreen. Arrow keys step through the table, and the copy-enabled pins are listed under the image. Open as many windows as you like to compare images side by side
• Column widths persist across launches and pin changes
• File size, dimensions, and created/modified dates are pinnable rows, so date columns and size sorting work like any tag
• Folders scan in the background with progress. A per-folder metadata cache makes reopening a folder near-instant, and a file is re-read only when its size or modified time changes
• Reopens your last folder on launch
• Drag and drop a folder or PNG onto the window. It also works with Open with or a path argument
• Reads metadata without decoding pixels. Thumbnails decode in the background with a bounded texture cache
• Handles ComfyUI prompt and workflow JSON (including Python-style NaN and non-ASCII text), plain key=value chunks, and custom keywords

Install

Download a binary from Releases for Windows, macOS, or Linux. Unzip and run.

Or build from source with Rust:

git clone https://github.com/Blakeem/png-metadata-gui
cd png-metadata-gui
cargo build --release

Linux needs GTK3 headers for the file dialog: sudo apt install libgtk-3-dev

Usage

png-metadata-gui                     # open empty, then drop a folder in
png-metadata-gui path/to/folder      # open a folder
png-metadata-gui image.png           # inspect one file
png-metadata-gui --dump image.png    # print flattened rows (debug builds)

Click a row to select it. Arrow keys navigate. Click a value in the tree to copy it, or use any 📋 button. Right-click pin chips in the toolbar to rename, reorder, remove, or toggle their copy button. The ⚙ button next to the pin box holds settings (ComfyUI title pins).

Settings, pins, and the folder metadata cache live in your per-user app-data directory (%APPDATA%\PNG Metadata GUI on Windows). The executable stays standalone.

Development

cargo test
cargo clippy --all-targets   # lints are deny-by-default, keep it clean

Pushing a tag like v0.1.0 builds all platforms and attaches the binaries to a GitHub Release.

License

MIT