Quick Diff

Generate side-by-side diffs between two pieces of code or text. Click the toolbar icon to open the diff tool.

Quick Diff compares two pieces of code or text and shows a clean, GitHub-style side-by-side diff. Click the toolbar icon, paste both versions (or load files), and hit Generate. WHAT YOU GET • Side-by-side view with syntax highlighting for JavaScript-like code • Character-level inline highlights — see exactly what changed inside a line • Moved-block detection — relocated code is tagged "moved to/from line N" instead of showing up as noisy delete + add walls • Foldable unchanged regions — long identical stretches collapse behind a "Show N unchanged lines" button, so you only read what changed • One-sided copy — start selecting in either column and only that side is selected, so copying a block never drags in the other version • Download as HTML — export the diff as a single self-contained file you can share or archive; it keeps the folding and copy behavior, no extension needed PRIVATE BY DESIGN Everything runs locally in your browser. The extension requests no permissions, makes no network requests, and collects no data. Your code never leaves your machine. HOW TO USE 1. Click the Quick Diff icon in the toolbar 2. Paste the old and new versions, or load them from files 3. Press "Generate diff" (or Ctrl/Cmd+Enter) 4. Fold, copy, or download the result