100% private. Both texts are compared entirely in your browser — nothing is uploaded, stored, or sent anywhere.
Text & Writing
Compare two texts
Paste the original and the modified version. Lines are compared one by one: green lines were added, red lines were removed.
Differences
Add both texts and press Compare.
When NOT to use Text Diff Checker
- It compares lines, not words — a one-word change marks the whole line as removed and re-added, so it can't highlight the exact word that changed.
- Very large documents (thousands of lines on both sides) are refused with a message, because an exact line diff grows quickly in the browser — split the document and compare it in parts.
Questions people ask
Is my text sent to a server?
No. This tool runs entirely in your browser using JavaScript. Your text is never uploaded, stored, or sent anywhere.
How does the comparison work?
It compares whole lines using a longest-common-subsequence match: lines only in the first text are marked removed, lines only in the second are marked added, and matching lines are unchanged.
Why is a moved paragraph shown as a removal and an addition?
Line diffs match content, not position — a paragraph that moved appears as removed from its old place and added in its new one.
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Found it useful? Share it with someone who needs it — the tool is free and runs entirely in the browser.