Paste two texts to find and highlight every difference. Character-level precision, side-by-side and inline views.
Use our Transform API to compare texts programmatically. JSON response with structured diffs, additions, deletions, and change counts.
curl https://agent-gateway-kappa.vercel.app/v1/agent-transform/api/diff \
-H "Content-Type: application/json" \
-d '{"original":"hello world","modified":"hello there"}'
Uses the classic Myers diff algorithm to find the minimum edit distance between two texts. Produces optimal, human-readable diffs.
Within changed lines, individual characters are highlighted to show exactly what changed — not just which lines differ.
Inline shows changes sequentially. Side by Side shows old and new in parallel. Unified shows the standard unified diff format.
Everything runs in your browser. Your text is never sent to any server. Works offline after the page loads.
Ctrl+Enter — Run diff comparison
Ctrl+Shift+S — Swap original and modified
Ctrl+Shift+X — Clear both text areas