How this diff tool works

Paste the original text on the left and the changed text on the right — the difference is computed live using the classic longest common subsequence algorithm, the same idea behind git diff. Removed lines are shown in red with a −, added lines in green with a +, and long unchanged blocks are collapsed so you only see what matters.

Everything runs in your browser — your text is never uploaded to a server, so it is safe for config files, contracts or code. Related tools: Find & Replace and the JSON Formatter & Validator.