JSON Validator

Paste your JSON and instantly know if it's valid. Error messages tell you exactly where the problem is. No server involved.

Input JSON

Output

FORMAT

Tips

Paste JSON in the left pane. Output updates instantly.

Runs entirely in your browser

How it works

JSON processing runs entirely in your browser using the native JSON.parse and JSON.stringify APIs. Output updates instantly as you type — no server round-trip needed.

Your data stays local

All processing happens inside your browser tab. The JSON you paste or type is never sent to a server — it stays entirely on your device.

Frequently asked questions

What does JSON validation check?

It checks that your JSON is syntactically correct — properly quoted keys, no trailing commas, balanced brackets, etc.

Does it check JSON Schema?

Not currently — this tool validates syntax only, not a schema or data contract.

Is my data private?

Yes. Validation uses JSON.parse in your browser. Nothing leaves your device.