Diff Checker
FreeSide-by-side text comparison with inline highlights and line numbers
diffcomparetextmerge
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How it works
1
Paste
Paste the original text on the left and the modified text on the right.
2
Compare
Click Compare to analyze both texts and highlight every addition, deletion, and change.
3
Review
Scroll through the side-by-side diff to review each difference with color-coded highlighting.
Frequently asked questions
Is my text sent to a server for comparison?+
No. The diff algorithm runs entirely in your browser. Your text never leaves your device, so you can safely compare contracts, code, credentials, or any private content.
What diff algorithm does it use?+
It uses a standard line-by-line diff algorithm similar to the Unix diff command. Added lines, removed lines, and modified lines are each highlighted in distinct colors.
Can I compare code files?+
Yes. The tool handles any plain text including source code, configuration files, JSON, XML, and more. It compares character by character within changed lines for precise highlighting.
Is there a size limit?+
There is no hard limit, but very large texts (over 100,000 lines) may slow down your browser. For typical use cases like comparing code files or documents, performance is instant.