Diff Checker
Compare two versions of text and see exactly what was added or removed.
How to use
- Paste the original text on the left.
- Paste the changed text on the right.
- Removed lines show in red, added lines in green.
How the Diff Checker works
Compares two blocks of text and highlights what was added, removed or changed — for reviewing edits, comparing config files or checking contract revisions.
Both inputs are split into lines and compared to find the longest common subsequence. Lines present only in the original are marked as removals; lines only in the revision are additions.
Worked example
Comparing two versions of a config file surfaces the three changed lines without you reading all 200.
Things worth knowing
- Comparison is line-based, so a single changed word marks the whole line as modified.
- Trailing whitespace and line-ending differences (CRLF versus LF) show as changes even when the visible text is identical.
- Both texts stay in your browser, which matters for contracts and credentials.
Frequently asked questions
Does it compare line by line?
Yes — it uses a longest-common-subsequence diff to align unchanged lines and highlight the rest.
Is my text private?
Completely — the comparison runs in your browser with no upload.
Why does everything show as changed?
Almost always mismatched line endings between a Windows-authored file and a Unix one. Normalise them first.