JSON Formatter & Validator

JSON (JavaScript Object Notation) is the default data format for web APIs, config files and logs. Machines happily read it as one long line, but people cannot. JSON formatting — also called pretty-printing or beautifying — re-indents that single line into a nested, readable structure so you can see which keys belong to which objects and where an array begins and ends.

Formatting also acts as a validation step. A formatter has to parse the document before it can re-print it, so an unterminated string, a trailing comma or a missing brace surfaces immediately with the position where the parser gave up. That is usually faster than hunting for the problem by eye.

Minifying is the reverse operation: every optional space and newline is stripped so the payload is as small as possible for transport or storage. Stringifying wraps the whole document in quotes and escapes it, which is what you need when JSON has to be embedded inside another JSON field, an environment variable, or a test fixture.

It runs entirely in your browser. Nothing you paste is uploaded, logged or stored, which means you can safely format a real API response containing customer records or internal IDs — something you should never do on a site that posts your input to a server.

It is also fast and free with no request limits, no account, and no interstitial ads over the editor. The tool area is deliberately kept clean; explanatory content lives below it, out of your way.

Beyond pretty-printing, you get minify, validate with line and column reporting, and both directions of string escaping in a single page, so you rarely need a second tab.

1. Paste your raw or minified JSON into the input panel.
2. Pick an indent width if you want something other than two spaces.
3. Press Format to pretty-print, or Minify to compact it.
4. Use Validate to check the document and see the exact error position if it fails.
5. Use Stringify or Unstringify to escape or unescape the JSON as a string literal.
6. Press Copy to put the result on your clipboard, or Clear to start over.