Code compare
Paste two versions of a file to see exactly which lines and words changed.
Sealed on this device
Runs in your browser. Nothing is uploaded.
Sealed
Differences
Paste code in both boxes to see the differences.
How it works
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Paste both versions
Paste the original on the left and the changed version on the right, or open two files from your device.
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Read the differences
Added, removed and changed lines are marked with their line numbers, and the exact words that changed are highlighted.
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Share the result
Copy or download the changes as a unified diff, the format used by Git and code review tools.
Frequently asked questions
Is my code uploaded to compare it?
No. The comparison runs in your browser, so source code, configuration files and credentials they might contain stay on your device.
What does “Ignore whitespace” do?
It treats lines as equal when they only differ in spaces, tabs or indentation. It’s useful after reformatting code, when only the indentation changed.
What is a unified diff?
It’s the standard text format for changes: removed lines start with -, added lines with +, and each group of changes shows a few lines of context. Git, patch and most code review tools can read it.
Can I compare any language?
Yes. The comparison works line by line on plain text, so it works for any programming language, JSON, YAML, CSV, SQL or configuration file.
How large can the files be?
Files with tens of thousands of lines compare in a moment. Long unchanged sections are folded, and you can expand them whenever you need the full context.