JSON Formatter & Validator

Paste JSON to validate, beautify or minify it — with clear error messages.

JSON input

Output

For developers

Paste API responses or config files to check syntax, then beautify for reading or minify for production. Error messages point at the exact problem — missing commas, trailing commas, unquoted keys.

Frequently Asked Questions

What errors does it catch?

Missing commas, trailing commas, single quotes, unquoted keys and mismatched brackets.

Is my JSON uploaded?

No — parsing happens locally in your browser.

What's the size limit?

Browser memory is the only limit; multi-megabyte files work fine.