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0 additions 0 deletions 0 lines Diffs are computed locally in your browser — nothing is uploaded.

Text Diff Checker — Free Online Tool

Paste two versions of a text and see every added and removed line highlighted instantly — perfect for comparing drafts, code, and configs.

Your line-by-line diff will appear here as you type.
Live diff — updates as you type
No sign-up needed
Free forever

How it works

1Paste your texts into the Original and Changed boxes above.
2Read the diff live — added lines turn green, removed lines turn red, instantly.
3Use Swap or Clear to flip the two texts or start a fresh comparison.

Frequently asked questions

Is my text uploaded to a server?

No. The comparison runs entirely in your browser with the open-source jsdiff library, so your text never leaves this page — nothing is uploaded or stored anywhere.

How does the diff work?

The tool compares your texts line by line using a longest-common-subsequence algorithm. Lines only in the changed text are marked as additions, lines only in the original as deletions, and identical lines as unchanged.

What if the diff library fails to load?

This page ships with a built-in fallback line-diff (plain JavaScript, no network needed), so comparisons keep working offline or if the CDN is unreachable — the diff results are identical.

Line-level diffing · live updates · 100% local — your text never leaves this page.