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JSON Formatter Documentation

Use the free JSON Formatter →

Validate, format, minify, copy, and download JSON with a quick browser-based parser.

What does it do?

Validate, format, minify, copy, and download JSON with a quick browser-based parser.

How does it work?

Strict mode uses the browser's JSON parser. JSON-like mode normalizes unquoted keys, single-quoted strings, comments, and trailing commas, including Python-style True, False, and None. Output can be pretty-printed or minified, recursively sort object keys, and display as code, numbered lines, or a navigable tree.

When to use it
  • Make an API response easier to inspect during debugging.
  • Validate a JSON configuration file before using it.
  • Minify a valid JSON payload for a compact test fixture.
Inputs and outputs
Input
Text, files, or values entered in the browser, depending on the tool.
Output
A result shown in the browser that can be reviewed or copied where supported.
Limitations
  • Uses JavaScript JSON values after normalization: integers beyond the safe numeric range can lose precision, and duplicate property names retain the last value. Quote large identifiers to preserve them.
  • JSON-like mode supports common JSON5/Python-style object syntax, not executable expressions, functions, undefined, or NaN.
Privacy and data handling

Inputs for this browser-side tool are processed locally and are not sent to SiteIndex. Normal page analytics may still be collected as described in the Privacy Policy. Read the Privacy Policy.

Results and sharing

Choose two- or four-space indentation, format or minify, and switch to numbered output. Copy or download valid JSON. Share result includes the output in the link; never share secrets. Editing input clears old output.

Use Share result to preview and copy a link. Anyone with the link can read the included details; nothing is saved on our server. Shared result links open read-only snapshots. Large results require a downloaded file instead.

How to use it

  1. Paste strict JSON or choose JSON5 / Python-like syntax to normalize unquoted keys, single quotes, comments, and trailing commas.
  2. Choose Format or Minify; optionally sort keys and select code, numbered, or tree output.
  3. Inspect any parser error, then copy, download, or share the result. Shared links contain the output, so never include secrets.

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