Stax

JSON Formatter

Format, beautify, minify, and validate JSON in your browser. Free, instant, 100% client-side. No login. Your data never leaves your device.

What is a JSON formatter?

A JSON formatter takes raw JSON — usually minified or pulled straight from an API response — and reformats it with consistent indentation and line breaks so it's actually readable. If you've ever stared at a 4,000-character single-line response from an API trying to figure out where one object ends and the next begins, you know the problem this tool solves.

Stax JSON Formatterformats, beautifies, minifies, and validates JSON instantly in your browser. There's no upload, no API call, no "sign in to format more than 5 KB." Paste, click, done.

How to use Stax JSON Formatter

  1. Paste your JSON into the input box (or click Sample to load an example).
  2. Click Format for a readable, indented version. Choose 2 spaces, 4 spaces, or tab indentation.
  3. Click Minify to strip all whitespace for production use.
  4. Click Validate to check syntax without changing anything.
  5. Hit Copy to copy the output to your clipboard.

Why format JSON?

Formatted JSON is dramatically easier to read, debug, and code-review. It also makes it possible to spot extra commas, missing brackets, and typos that would otherwise hide in a wall of text. For minified payloads traveling over the wire, formatting is essential the moment something fails in production and you need to inspect the response by hand.

Privacy and data handling

Everything runs in your browser's JavaScript engine. We do not send your JSON to any server. We do not store it. There is no "processing" happening anywhere except on your device. This matters when you're working with API responses that contain credentials, customer data, or anything else you wouldn't want to upload to a random website you found via Google.

Frequently asked questions

What is JSON formatting?
JSON formatting (also called beautifying or pretty-printing) means taking a compact or messy JSON string and adding indentation, line breaks, and whitespace so it's readable. Stax JSON Formatter does this instantly in your browser.
Is my JSON sent to your servers?
No. The JSON Formatter runs entirely in your browser using JavaScript. Your data is never uploaded, logged, or stored anywhere — Stax has no backend that processes your input.
What's the difference between Format and Minify?
Format expands JSON with indentation and newlines for human readability. Minify removes all whitespace to make the JSON as small as possible — useful for production payloads, embedding in HTML, or saving bandwidth.
What if my JSON is invalid?
When JSON is invalid, the formatter shows the parser's exact error message (often with the position of the problem) so you can fix it. Common issues include trailing commas, single quotes instead of double quotes, comments (which JSON doesn't support), and unquoted keys.
Does this work offline?
Yes. Once the page loads, all formatting happens locally. You can disconnect from the internet and the tool keeps working.

Related tools