Is anything I paste or upload sent to a server?

No. theDiff is a static page with no backend — every comparison (text, file, JSON, image) runs entirely in your browser using JavaScript and the Canvas API. You can disconnect from the internet after the page loads (once the editor engine has loaded from its CDN) and keep comparing.

How is the JSON diff different from just comparing the text?

JSON Diff parses both sides and compares them structurally, by key and index — not line by line. Two JSON documents with the same keys and values but in a different order, or reformatted with different indentation, will correctly show as identical, which a plain text diff would get wrong.

Can I compare binary files or PDFs?

File Diff detects binary files and, instead of a meaningless byte-level visual diff, compares their size and a SHA-256 hash so you can honestly tell whether they're identical or different. Full PDF/spreadsheet diffing isn't supported yet.

Can I share a diff with someone else?

There's no "share via link" — that would need a server to store your content, which this project deliberately doesn't have. Instead, export a real unified patch file or a self-contained static HTML report and send that.

Completely — no sign-up, no ads, no tracking, no paid tier. It's a static page; there isn't even a server to bill anyone from.

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Free · Ad-free · No sign-up · 100% private

Compare text, code, files, JSON and images — entirely in your browser

theDiff runs on Monaco, the same editor engine that powers VS Code: side-by-side or unified diff views, character-level highlighting, and syntax highlighting for 60+ languages. Nothing you paste or upload is ever sent anywhere — there is no server.

Keyboard: Ctrl+Shift+↑/↓ jumps between changes once a diff is loaded.

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