JSON Schema Validator

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.

It validates your JSON data against your JSON Schema using the full draft specification — types, required properties, formats, enums, nested objects and array rules. When something fails it lists the exact path and the rule that was broken, so you can fix it quickly.

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.