Text Diff Checker

This free text compare tool shows exactly what changed between two versions of a text. Paste the original on the left and the new version on the right, hit Compare, and every removed line is marked in red while every added line is marked in green, aligned side by side. It uses a longest-common-subsequence (LCS) algorithm — the same approach behind git diff — so moves and rewrites are matched sensibly rather than shown as wholesale deletion plus re-adding.

Common uses: comparing two versions of a contract or article before sending, checking what a colleague changed in shared copy, verifying code snippets or config files, and spotting accidental edits in translated text. Options let you ignore case or whitespace-only differences when those don't matter. Everything runs entirely in your browser — your text is never uploaded, stored or sent anywhere.