Text Diff Checker
Compare two texts and highlight added, removed and changed lines and words.
Runs in your browser. Your input is processed on your device and is not uploaded to our server.
How to use the Text Diff Checker
- Paste the original text on the left and the changed text on the right.
- Choose line or word comparison and whether to ignore case or whitespace.
- Click Compare to see additions in green and removals in red.
How the comparison works
The checker uses the longest common subsequence algorithm, the same idea behind version-control diffs, to find the smallest set of insertions and deletions that turns the first text into the second. Line mode is best for code and lists; word mode is best for prose.
Frequently asked questions
Is there a size limit?
The comparison runs in your browser. Texts of up to a few thousand lines compare quickly; very large inputs may be slow on older devices.
Are my texts uploaded?
No. Both texts stay in your browser.