Text Diff Checker
Paste the original and modified text, then compare — differences are highlighted line by line.
How the comparison works
The tool computes a longest-common-subsequence diff over lines — the same core approach used by git diff. Lines present only in the modified text are highlighted green (added), lines present only in the original are red (removed), and matching lines are shown without highlighting for context.
Frequently asked questions
Is my text uploaded anywhere?
No. The comparison runs entirely in your browser; neither text ever leaves your device.
Is there a size limit?
Texts up to roughly 2,000 lines each compare instantly. Beyond that the tool will ask you to shorten the input to keep your browser responsive.