JSON formatter & validator

Beautify, minify and validate JSON with precise error locations.

100% private. Runs entirely in your browser — nothing you enter is ever sent anywhere.

How it works — step by step

  1. Paste your JSON into the editor (or drop a .json file).
  2. Click "Format" for pretty-printed output, or "Minify" for a compact single line.
  3. Errors are pinpointed with the line and column so you can fix them fast.

Frequently asked questions

Is my JSON data sent anywhere?

No. Parsing and formatting run entirely in your browser, so API responses, config files and payloads with secrets stay on your machine.

How large a JSON file can I format?

Files up to tens of megabytes work fine in a modern browser — far beyond most online formatters that cap input size.

What does the validator check?

Strict JSON syntax (RFC 8259): quoting, commas, brackets and value types. The exact position of the first error is reported.

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