Compare text/code online — side-by-side & unified diff

Code Diff is a free tool to compare text, code, and JSON online. Paste “Original” and “Modified” content, then view differences side-by-side or as a unified diff. No sign-up and no uploads: everything runs in your browser.

Original
Modified
Unified diff

Frequently asked questions

Can I compare code and JSON?

Yes, it works great with plain text, source code, and JSON. Choose side-by-side or unified diff view.

Are my data uploaded to a server?

No. Everything happens in your browser. No text is sent or stored.

Can I download the patch?

You can copy the diff or download changes.patch with correct line breaks.

About Code Diff

Code Diff is an online tool to compare code, text, or JSON instantly. It’s ideal for developers, writers, and translators who need to find differences between versions of text files.

Unlike other diff tools, Code Diff runs fully in your browser — no uploads, no privacy risk, and no limits.