kawari

Private diffs. Shareable URLs.

A privacy-focused diff tool. Paste two texts, see what changed. No accounts, no tracking, works offline.

Features

• No server; everything runs locally in the browser
• Share via URL: diffs are compressed and encoded in the URL
• Works offline as an installable PWA
• Minimap: visual overview for navigating large diffs
• Drag and drop files directly into the text areas
• Download patch files compatible with git apply
• Ignore options: whitespace, quote style (" vs ')
• Keyboard shortcuts:
  • Cmd/Ctrl+Enter: compare texts
  • j/n: next change
  • k/p: previous change
  • e: edit (back to input)
  • Shift+click on collapsed section: expand/collapse all

Contributing

Please do! I'd appreciate bug reports, improvements (however minor), suggestions…

The tool uses vanilla JavaScript, HTML, and CSS. To run locally:

1. Clone the repository: git clone https://github.com/welpo/kawari.git
2. Navigate to the app directory: cd diff/app
3. Start a local server: python3 -m http.server
4. Visit http://localhost:8000 in your browser

The important files are:

• app.js: UI logic and event handling
• diff.js: diff algorithms (Myers, Patience) and patch generation
• diff.worker.js: Web Worker for off-main-thread diffing
• styles.css: styles
• index.html: structure

Tests

Tests live in tests/ and use Node's built-in test runner:

node --test tests/*.mjs

• patch.test.mjs: verifies generated patches can be applied with git apply. Each test case in tests/cases/ has an original.txt and modified.txt.
• normalization.test.mjs: tests whitespace/quote normalization logic.

Need help?

Something not working? Have an idea? Let me know!

• Questions or ideas → start a discussion
• Found a bug? → report it here
• Feature request? → let me know

License

kawari is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.