JSON Formatter - Validate and Beautify Free

It validates your input and shows a clear error message pointing at the problem, so you can fix it fast.

Yes. Switch between pretty-printed and compact output depending on whether a human or a machine reads it.

Yes. Formatting runs entirely in your browser, so your JSON never leaves your device.

Yes. Paste large API responses or config files - validation and formatting stay fast.

No. Paste, format, copy - no account and no watermarks.

A validator checks strict JSON syntax — quotes, commas, brackets and data types — and reports the exact position when parsing fails. A formatter only rearranges valid JSON for reading. Here both run together, so beautified output means your API response or config file is also structurally sound.

Pretty-printed JSON with indentation is for humans debugging a payload or reading a config file. Minified JSON strips every unnecessary space so machines transfer it faster and store it smaller. Format while you develop, then minify the same data before production use.

The usual culprits are a trailing comma after the last item, single quotes instead of double quotes, unquoted keys, or comments inside the data. The error message points at the position so you can fix that spot, balance the brackets, and validate again until the whole structure parses.

In JSON, numbers, booleans and null must sit outside quotes, while everything wrapped in double quotes is read as a string. Swapping quote styles silently changes data types, and APIs often reject such payloads. The formatted tree view makes every value and its intended type easy to inspect.

Paste raw API responses, webhook payloads or configuration files to reveal their nested structure, spot missing fields and untangle one-line data exports. Because formatting and validation run entirely in your browser with no network requests, even payloads containing tokens or keys stay on your device.