Text Diff — Compare Two Texts Line by Line
About the Text Difference Checker
Paste two versions of a text and this tool highlights exactly what changed: lines only in the first text, lines only in the second, and their positions side by side. It uses the same longest-common-subsequence algorithm that powers diff tools, so reordered but identical text is not reported as a change.
It is ideal for reviewing edits to articles, contracts, configuration files or code snippets without emailing files back and forth. Both texts are processed locally in your browser.
How to use the Text Difference Checker
- Paste the original text into the left box.
- Paste the changed text into the right box.
- The diff appears instantly — red lines were removed, green lines were added.
Frequently asked questions
Does the diff handle changes within a line?
This tool compares line by line and flags whole changed lines. For character-level highlighting inside a line, check the paired lines in the output — the surrounding context makes most edits obvious.
How large can the texts be?
Comfortably thousands of lines. For extremely large inputs the tool warns before running the quadratic comparison.
Is my text uploaded anywhere?
No. The comparison runs entirely in your browser with JavaScript.
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