Diff Checker
Compare two texts side-by-side or unified — line, word, and character-level diff with the Myers algorithm. File input, .patch export, ignore whitespace/case. 100% private.
About Diff Checker
Compare two texts side-by-side or unified — line, word, and character-level diff with the Myers algorithm. File input, .patch export, ignore whitespace/case. 100% private. Everything runs locally in your browser — your data never leaves your device.
How to use
- Enter your input in the tool above.
- Adjust any options to your preference.
- Use the Copy or Download buttons to save the result.
- Everything happens locally — your data never leaves your browser.
FAQ
Is my text uploaded anywhere?
No. All comparison happens in your browser using the Myers diff algorithm. Your text never leaves your device.
What diff algorithm is used?
The Myers diff algorithm — the same algorithm used by Git. It produces a minimal edit script and runs in O(ND) time where N is the total lines and D is the number of differences.
Can I compare files?
Yes. Click 'Load file' under either panel to load a .txt, .md, .json, .csv, or source code file. Files are read client-side — nothing is uploaded.
Can I export the diff?
Yes. Click 'Download .patch' to get a unified diff file compatible with the patch command, or 'Copy .patch' to copy it to your clipboard.
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