Text & Dev · Free to use
JSON Formatter & Validator
Paste JSON to pretty-print or minify it and instantly catch syntax errors. Nothing is sent to a server.
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How to use the json formatter
- 1Paste your JSON.
- 2Choose Beautify or Minify.
- 3Fix any reported error, then copy the output.
This tool runs in your browser. The text, files and values you enter are not uploaded to our server.
About the json formatter
A JSON formatter beautifies (pretty-prints) or minifies JSON and validates it, flagging syntax errors with the parser message. Developers use it to read API responses, debug payloads and shrink config. Parsing happens in your browser, so even sensitive payloads stay local.
Frequently asked questions
Is this tool free?
Yes — completely free, no signup, no watermark and no limits. Startup OG funds the site through its directory and partner program, not paywalled tools.
Is my file or data uploaded anywhere?
No. Everything runs locally in your browser — your file or text never leaves your device and nothing is stored on a server.
What does "beautify JSON" mean?
It re-indents JSON with consistent spacing and line breaks so a dense API response becomes human-readable. Minify does the reverse for the smallest size.
Why is my JSON invalid?
The usual culprits are trailing commas, single quotes instead of double quotes, unquoted keys, or a missing bracket. The error message points to the spot.