Text Diff Checker — Compare Two Texts
Compare two blocks of text and highlight added and removed lines.
Lines in green (+) were added, red (−) were removed. Matching lines are aligned so only real changes stand out. Runs entirely in your browser.
Paste an original and a changed version of any text to see exactly what differs. A line-level diff aligns matching lines and highlights additions in green and deletions in red, so real changes stand out instead of being buried. Useful for comparing drafts, config files, code snippets, contracts and translations. Everything runs locally in your browser.
How to use the Text Diff Checker
- Paste the original text in the left box.
- Paste the changed version in the right box.
- Read the diff: green lines were added, red lines were removed.
Frequently asked questions
How does the diff decide what changed?
It uses a longest-common-subsequence algorithm to align unchanged lines first, then marks the remaining lines as added or removed — the same approach code-diff tools use, so inserts don't shift everything below them.
Can I compare code or config files?
Yes. The diff is line-based and works on any plain text — code, JSON, CSV, contracts or prose.
Is my text sent to a server?
No. The comparison runs entirely in your browser; neither version leaves your device.