Text Diff Checker
Paste two versions of a text and see exactly what changed. The tool compares them line by line, highlights the changed words, and reports how many lines were added, removed or left unchanged, along with an overall similarity score. Everything runs in your browser — nothing is uploaded.
Differences
How to use
- Paste the older version into Original text and the newer version into Changed text.
- Tick Ignore whitespace or Ignore case if spacing or capitalisation should not count as a change.
- Press Compare. Removed lines are red, added lines are green, and changed words are highlighted.
- Switch between Side by side and Unified views to read the diff the way you prefer.
- Use Swap texts to reverse the direction, or Clear to start over.
Reading the results
The similarity score tells you how alike the two texts are: 100% means identical, 0% means nothing matches. In unified view, lines starting with − exist only in the original and lines starting with + exist only in the changed text. When a line was edited rather than fully added or removed, the exact changed words get a highlighted background so you can spot the edit instantly.
Privacy
The comparison is done entirely with JavaScript on your device. Your text is never sent to any server or stored anywhere.