🧰 HeavyToolz
{ }

JSON Formatter & Validator

Format, validate, and minify JSON with clear, precise error messages.

Frequently asked questions

Is my JSON data uploaded anywhere?

No. Formatting and validation run entirely client-side in your browser; nothing is transmitted to any server.

What happens if my JSON is invalid?

The tool shows the exact parser error message so you can quickly locate and fix the problem.

Can I minify JSON instead of formatting it?

Yes, use the Minify button to collapse formatted JSON into a single compact line.

Related tools

⇄ Base64 Encoder / Decoder Encode text to Base64 or decode Base64 back to text, with full Unicode support. % URL Encoder / Decoder Encode text for safe use in URLs, or decode percent-encoded URLs back to plain text. 🪪 JWT Decoder Decode a JSON Web Token's header and payload to inspect its claims — no signature verification. 🎯 Regex Tester Test regular expressions against sample text with live match highlighting.