Diff Checker
Compare two blocks of text and see exactly what was added, removed, or changed, line by line.
Compare two texts line by line
Paste your original text on the left and the changed version on the right, then hit Compare. Lines only in the original are highlighted as removed, lines only in the new version are highlighted as added, and unchanged lines are shown for context — the same idea as a git diff, but for any text.
Common uses
- Reviewing edits to a contract, essay, or article draft.
- Comparing two versions of a config file or code snippet.
- Checking exactly what changed between two exports of the same data.
- Spotting accidental changes in a copy-pasted block of text.
Frequently asked questions
How does this diff checker decide what changed?
It compares the two texts line by line using a longest-common-subsequence algorithm — the same general approach used by tools like git diff — so it finds the smallest set of added and removed lines needed to turn the left text into the right one, rather than just flagging every line as different.
Does it ignore whitespace or letter case?
By default it compares lines exactly as typed. Turn on "Ignore whitespace" or "Ignore case" above the boxes if you want trailing spaces or capitalization differences to be treated as no change.
Can I compare code, not just plain text?
Yes — the diff is purely line-based text comparison, so it works equally well for code, config files, CSV rows, or prose.
Is my text uploaded anywhere?
No — the comparison runs entirely in your browser with JavaScript. Nothing you paste is sent to a server, which matters if you're comparing private code or documents.