Free Text Diff Checker
See exactly what changed between two versions. Paste the original and the modified text, and this free diff tool highlights added lines in green and removed lines in red — a precise, line-by-line visual diff with zero setup.
How to Use the Text Diff Checker
- Paste the original text on the left.
- Paste the modified version on the right.
- Click “Show diff”.
- Review green additions and red removals.
Features
True LCS-based line diff with color-coded output: green for added lines, red for removed, muted for unchanged — plus a legend with added/removed counts. Handles large inputs with an automatic fast approximate mode past ~2,000 lines, and everything renders in a scrollable monospace view.
Benefits & Use Cases
Writers review exactly what an editor changed. Developers compare config files and data snapshots. Students see how their draft evolved between versions. Translators verify only intended segments changed.
Tips
Diffs are line-based, so a single changed word marks its whole line — keep lines short for precise diffs. Trailing whitespace differences count as changes; trim both sides first with Text Trimmer for a cleaner diff. The legend totals tell you the change volume at a glance.
Frequently Asked Questions
Is the diff checker free?
Yes, free and unlimited.
What do the colors mean?
Green lines were added, red lines were removed, grey lines are unchanged.
Why is a whole line marked changed?
Diffs work per line — any edit within a line flags the entire line.
Can it handle large files?
Yes — very large inputs automatically use a fast approximate diff.
Are my texts uploaded?
No, the diff is computed locally in your browser.
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