Diff Checker
Compare two blocks of text or code and instantly see what was added, removed and changed — side-by-side or inline, with word-level highlighting. Ignore case or whitespace, swap sides, and copy the unified diff. Everything runs locally in your browser — nothing is uploaded.
Paste text into both boxes to see the differences.
About this diff checker
An LCS algorithm finds the smallest set of added and removed lines between the two versions.
When a line changes, the exact words that differ are highlighted so spotting edits is effortless.
Switch between a side-by-side comparison and a compact inline unified diff.
Optionally ignore case or leading/trailing whitespace to focus on meaningful changes.
Export a +/- unified diff you can paste into a review or a commit message.
Both texts are compared in your browser — nothing is ever uploaded.