JSON Formatter & Validator
Format, beautify, validate and minify JSON online for free. Instant syntax error messages with line numbers. Runs fully in your browser.
Frequently asked questions
- Are my files uploaded to a server?
- No. This tool runs entirely in your browser using JavaScript — your files never leave your device.
- Does it validate JSON?
- Yes — invalid JSON shows the exact parser error so you can find and fix the problem.
- Can I minify JSON too?
- Yes, the Minify button removes all whitespace for the smallest possible payload.