JSON Formatter

Prettify, minify, and validate JSON with inline error highlighting and configurable indentation.

Backend developers formatting raw API responses while debugging integrations.

How to use it

  1. Paste your JSON

    Drop in the raw or minified JSON from an API response, log line, or config file.

  2. Choose indentation

    Pick 2 spaces, 4 spaces, or tabs. If the JSON is invalid, the tool flags the error so you can fix it.

  3. Prettify, minify, or copy

    Format it for reading, minify it for production, optionally sort keys, then copy the result.

Why use this tool?

JSON is the language APIs, config files, and logs speak in, but it usually arrives minified — one giant line with no spacing — which is almost impossible to read or debug. When something is wrong, a single missing comma or unclosed bracket can break an entire payload, and hunting for it in a wall of text wastes real time. A formatter turns that mess into clean, indented, colour-readable structure and points straight at syntax errors. This tool prettifies JSON with your choice of indentation, validates it and highlights where parsing fails, can minify it back down for production, and optionally sorts object keys alphabetically so two objects are easy to compare. It all runs in your browser in pure JavaScript, which matters more than it sounds: developers often paste API responses, tokens, or config containing secrets into online formatters, and here that data never leaves your device or touches a server. No account, no limits — paste, format, copy.

Common use cases

API debugging

Make a raw API response readable instantly to inspect field names, nesting, and values while developing.

Config file editing

Prettify dense config like package.json or tsconfig.json, edit it, then minify if needed.

Validation

Confirm a JSON string is syntactically valid — and find exactly where it breaks — before your code tries to parse it.

Comparing objects

Sort keys alphabetically on two payloads so a diff highlights real differences instead of key-order noise.

Documentation & sharing

Clean up example payloads before pasting them into docs, tickets, or a pull request.

Frequently asked questions

Is my JSON sent to a server?

No. All formatting and validation happen in your browser, so sensitive payloads, tokens, and secrets never leave your device.

Does it support comments or JSON5?

No — it follows standard JSON (RFC 8259). Comments or trailing commas will be reported as a parse error.

How does it help me find errors?

When the JSON is invalid, the parser reports the failure so you can locate the missing comma, quote, or bracket quickly.

What does "Sort keys" do?

It reorders every object’s keys alphabetically, which makes large objects easier to scan and makes two payloads directly comparable.

What is the difference between prettify and minify?

Prettify adds indentation and line breaks for humans; minify strips all whitespace to produce the smallest possible string for production or transport.

Is there a size limit?

No hard limit, but very large documents (over ~10MB) may format slowly depending on your device.

Does formatting change my data?

No. It only changes whitespace and, if you choose, key order — the actual values and structure are untouched.

Is it free?

Yes — completely free, no sign-up, and no usage limits.

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