• 100% Free
  • No Sign-Up
  • No Credit Card
  • No Free Trial
  • No Pro Tier
  • No Watermarks

Nothing is uploaded. Just open it and start.

A code compare tool that stays out of your way

Paste or upload your original and modified code and watch every addition, deletion, and change highlighted live. No sign-up, no watermarks, nothing between you and your diff.

Side-by-side or unified

Switch layouts any time — both stay in sync with whatever you've pasted, typed, or uploaded.

100+ languages

Syntax highlighting for JavaScript, Python, Rust, SQL, YAML, and dozens more, auto-detected on upload.

Ignore whitespace or case

Toggle either on to cut through noisy indentation or casing changes and focus on what actually changed.

100% private, 100% client-side

Your code never leaves your browser. There's no server round trip, ever.

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Frequently asked questions

Is my code uploaded to a server?
No. Every comparison happens entirely in your browser — nothing you paste or upload is sent, logged, or stored anywhere.
What's the difference between side-by-side and unified?
Side-by-side shows both versions in their own editable pane with matching lines aligned. Unified shows a single pane with removed and added lines interleaved, like a git diff.
How does ignoring whitespace or case work?
Ignore whitespace treats any run of spaces/tabs/line breaks as equivalent, so differing indentation or trailing spaces won't show as changes. Ignore case compares text lowercased. Both only affect what's highlighted as different — your original text is never modified.
What can I download?
A standard unified diff (.diff) of your comparison — the same format produced by `diff -u` or `git diff` — which you can share, save, or apply with any patch tool.
What size of file can I upload?
Up to 10MB per file via the Options menu. Pasting or typing directly into either pane has no hard limit.
Is the Code Compare tool really free?
It is. No sign-up, no payment details, no expiry date, and no upgrade prompt hiding the useful parts. Both diff views, all 100+ languages, and file upload are included — nothing is reserved for a paid plan. Hosting is paid for by a single unobtrusive ad slot and nothing else.
Is there anything to install or register for?
No. It's a plain web page: no account, no extension, no desktop app, no email capture. Paste your original and modified versions and the diff renders immediately.