A JSON formatter that never sees your data
JSON that arrives minified — one long unbroken line from an API response, a log file, or a config export — is genuinely hard to read or debug by eye. This tool reformats it instantly with proper indentation, or does the reverse and strips it down to the smallest possible size, all directly inside your browser. Since JSON frequently contains real data — API keys, user records, configuration — never uploading it anywhere isn't a nice-to-have here, it's the point.
How it works
- Paste your JSON. Valid or invalid — either way, you'll see immediate feedback.
- Beautify or minify. Pick indentation width, or strip it down to a single compact line.
- Copy the result. One click grabs the formatted or minified output.
Reading a validation error
When JSON is invalid, the error message points at specifically what the parser couldn't make sense of. The most common culprits: a trailing comma after the last item in an object or array (valid in JavaScript, invalid in strict JSON), an object key that isn't wrapped in double quotes, a stray single quote where JSON requires double quotes, or a missing closing brace or bracket somewhere earlier in the document than the error position might suggest.
When to beautify, when to minify
Beautified JSON is for humans — debugging an API response, reviewing a config file, or understanding a data structure someone else wrote. Minified JSON is for machines — smaller payloads transfer faster over a network, and production code has no need for the extra whitespace that only exists to help a person read it. Most workflows use both at different points: beautified while developing and debugging, minified once it's actually being sent or stored.
Your data stays private
Nothing you paste into this tool is sent anywhere — every operation happens directly in your browser using the same JSON parser built into JavaScript itself. See our Privacy Policy for full details.
Frequently asked questions
+Is this JSON formatter really free, with no sign up?
Yes. There's no account and no limit on how much JSON you can format or validate.
+What does 'Beautify' actually do?
It parses your JSON and re-outputs it with consistent indentation and line breaks, making nested objects and arrays easy to read at a glance — useful for JSON that arrived as one long unbroken line from an API response or log file.
+What's the difference between Beautify and Minify?
Beautify adds indentation and line breaks for readability. Minify does the opposite — it strips all unnecessary whitespace to produce the smallest possible file size, which is what you'd typically want before actually sending JSON over a network or shipping it in production.
+How does the validator find errors?
It uses the browser's own built-in JSON parser, the same one that powers JSON.parse() in JavaScript. If your JSON is invalid, the error message tells you specifically what the parser choked on — often a missing comma, an extra trailing comma, or an unquoted key.
+Is my JSON data sent anywhere?
No. Every operation happens directly in your browser — nothing you paste is ever uploaded or logged, which matters if your JSON contains real data from an API response, config file, or database export.