Diff Highlighter

Compare two blocks of text or code side-by-side online. Highlights additions, deletions, and modified lines with zero server uploads.

100% Client-Side / Offline Buy me a coffee
Input
Ready
Output
Ready

How It Works

Paste original text and modified text separated by ===MODIFIED=== to view added and deleted lines side-by-side.

Frequently Asked Questions

Is my data private and secure?

Yes. All operations run 100% inside your local web browser runtime using client-side JavaScript. No text, tokens, code, or personal data are ever uploaded to an external server or cloud service.

Can I run this tool completely offline?

Yes. You can install the packaged Manifest V3 Chrome Extension version from GitHub or save this standalone HTML page locally to use without an internet connection.

Is this tool free and open source?

Yes, all tools are 100% free and licensed under the permissive MIT license. If this tool helped you solve an annoyance, you can support development at ko-fi.com/jju1s.