JSON Compare

Paste your input into the box above and the result appears instantly below — nothing to press and nothing to upload. It runs entirely in your browser, so you can copy the output or download it as a file. If the input has an error, a clear message tells you exactly what to fix.

Yes on both counts. It is completely free with no signup or limits, and it is private because everything runs locally in your browser — your data is never sent to a server. That makes it safe for production schemas, tokens and payloads, and it keeps working offline once the page has loaded.

Each line is prefixed to show what changed: "+" means the key exists only in the second document, "-" means it exists only in the first, and "~" means the value differs, shown as old → new. Identical documents report that no differences were found.

There is no fixed limit because nothing is uploaded — the only constraint is your device's memory, so typical inputs process instantly. The engine loads on first use and is cached afterwards, so repeat runs start immediately.

Yes. It runs in any modern browser on Windows, Mac, Linux, iPhone and Android with nothing to install, and works offline once loaded. The result can be copied or downloaded on any device.