Format, Beautify & Validate JSON Online — Free, Private
Paste messy JSON and instantly beautify, minify, or validate it. This free online JSON formatter highlights syntax, reports exact error positions, and runs entirely client-side — ideal for developers debugging APIs or config files quickly.
Why this tool is useful
- Debug API responses and config files faster with readable formatting.
- Catch syntax errors with precise line and column feedback.
- Minify JSON to save bandwidth before deployment.
How it works (client-side)
- Paste your JSON into the input area.
- Choose Beautify (pretty-print) or Minify (compact).
- The browser's native JSON parser validates and reformats it locally.
Frequently asked questions
Can it handle large JSON files?
Yes — formatting is done in-browser, so files of several megabytes typically format in under a second.
Will it tell me where the error is?
Yes. If your JSON is invalid, you'll see the error message with the character position so you can fix it.
Is my data sent anywhere?
No. Parsing and formatting happen locally; your JSON never leaves your browser.