Text diff checker
Paste the original and the changed version to see exactly what was added, removed or edited — line by line, with changed words highlighted.
Runs entirely in your browser. Nothing you enter is sent to a server.
How the comparison works
The checker finds the longest common subsequence of lines — the largest set of lines both versions share in order — and marks everything else as added or removed. When a removed line is directly replaced by an added one, it’s shown as a change, with the individual words that differ highlighted.
Good for
- Spotting edits between two drafts of a contract, essay or email.
- Comparing config files or code snippets without opening Git.
- Checking what changed in terms and conditions.
Comparing JSON? Format both sides first with the JSON formatter (sort keys too) so formatting differences don’t hide real changes. To check two files are byte-for-byte identical, compare their hashes with the hash generator.
Frequently asked questions
Is my text uploaded?
No. The comparison runs in your browser.
How large can the texts be?
A few thousand lines each works well. Very large files are refused rather than freezing your browser.
Can I ignore spacing differences?
Yes. Tick “Ignore whitespace” to treat lines that differ only in spaces or tabs as equal.