diff checker

Compare two texts.

Paste two versions of any text. See exactly what was added, removed, and unchanged with a line-by-line LCS diff.

+ 2 added- 2 removed= 1 unchanged
1+the quick red fox
1-the quick brown fox
22 jumps over
3+the lazy cat
3-the lazy dog
AIExplain diff formats

Frequently asked

Is this tool free?
Yes. The diff checker is completely free. Compare any two texts with no usage limits.
Do I need to sign up?
No. Paste your two texts and see the diff instantly. No account needed.
Is my data private?
The comparison runs entirely in your browser using a Longest Common Subsequence algorithm. Your text is never sent to any server, so it is safe to compare confidential documents.
Is there a size limit?
Each input is limited to 5000 lines to keep the browser responsive. For most use cases this is more than enough.