JSON Formatter

The JSON Formatter is a free online json formatter and json beautifier that turns raw or minified JSON into clean, properly indented output in seconds. It's built for the moments every developer hits constantly: pasting a squashed API response into a readable shape, reviewing a teammate's config file, or checking that a payload you're about to send actually parses. Front-end and back-end engineers, QA testers poking at API responses, and anyone maintaining JSON-based config files (package.json, tsconfig.json, OpenAPI specs) will find themselves reaching for it daily.

Beyond pretty-printing, the tool doubles as a strict json validator: invalid JSON — a missing comma, an unquoted key, a trailing bracket, a stray comment (JSON doesn't allow them) — is caught instantly, with an error message that names the problem instead of leaving you to scan character by character. Large, deeply nested payloads become much easier to scan once keys are sorted alphabetically, which is especially useful when diffing two versions of the same object or hunting for a specific field in a response with hundreds of keys. When you're done reviewing, the same tool can minify the JSON back down, stripping whitespace before it ships to production or gets embedded in a script tag.

Under the hood the formatter uses the browser's native JSON parser, so the validation you see here is exactly what JSON.parse would do in your own code — no approximated or lenient third-party parser papering over real errors. Formatting, minifying and key-sorting all happen instantly as you type or paste, with no network request and no size limit beyond what your browser's memory can hold, which makes it comfortable to use even on multi-megabyte API dumps.

Because everything runs client-side in JavaScript, sensitive payloads — auth tokens, customer records, internal API responses — never leave your device, which makes this a safe way to format json online even for data you wouldn't want to paste into a random third-party service.