Diff checker
Compare two texts line by line and see exactly what changed. Runs in your browser.
Runs 100% in your browser Differences
How to compare two texts
- Paste both versions. Original on the left, changed on the right.
- Read the diff. Removed lines are red, added lines green, unchanged lines plain.
About diffing text
A diff shows precisely what changed between two versions of a document — code, config, prose or data. Comparing line by line (rather than character by character) keeps the output readable and matches what you see in code review. Everything stays on your device, so it's safe for comparing sensitive files.
Frequently asked questions
- It compares the two texts line by line using a longest-common-subsequence algorithm, then marks lines that were added, removed or unchanged — the same approach as git and most diff tools.
- Yes, lines must match exactly to be considered unchanged. Trim or normalise beforehand if you want to ignore those differences.
- Any text works. For comparing JSON by structure rather than lines, use the dedicated JSON diff tool instead.
- No — the comparison runs entirely in your browser.