Paste two versions of text or code and instantly see what changed, side by side.
Runs in your browser
| Original | Changed | |||
|---|---|---|---|---|
Click Compare to see the diff.
A diff checker compares two blocks of text or code and visually highlights exactly what was added, removed, or left unchanged line by line. It is used by developers reviewing pull requests, writers tracking document revisions, and sysadmins comparing configuration files before and after a change. Paste the original version on the left and the updated version on the right, then click Compare. The tool uses a Longest Common Subsequence (LCS) algorithm the same method used by Git to produce a side-by-side diff with colour-coded additions (green), deletions (red), and unchanged lines (grey). All processing happens in your browser; no text is sent to a server.
Paste your original text into the Original panel on the left and your updated version into the Changed panel on the right. The diff runs automatically when both panels have content. Use the checkboxes to ignore whitespace differences, ignore case, or hide unchanged lines. The colour-coded diff table below shows additions in green and removals in red, with line numbers on both sides. Click Copy diff to copy a unified diff string to your clipboard useful for pasting into pull request descriptions or bug reports.