JSON Formatter & Validator

Paste your JSON to beautify, validate or minify it in one click. Errors are shown with their exact line and column, so you can fix broken JSON fast. Everything runs in your browser; your data is never uploaded.

How to use the JSON Formatter

  1. 1

    Paste or open your JSON

    Paste JSON into the left box, or open a .json file from your computer.

  2. 2

    Check if it is valid

    The tool checks your JSON as you type. If something is wrong, it shows the line and column of the error.

  3. 3

    Format or minify

    Click Format to make it readable with 2 spaces, 4 spaces or tabs, or Minify to remove all spaces for the smallest size.

  4. 4

    Copy or download

    Copy the result to your clipboard or download it as a .json file.

Features

  • Validate as you type

    See instantly whether your JSON is valid, with the size and number of keys.

  • Exact error location

    Invalid JSON shows the line and column of the problem.

  • Beautify or minify

    Pretty-print with 2 spaces, 4 spaces or tabs, or compress to one line.

  • Sort keys

    Optionally sort object keys A to Z, at every level, for easy comparing.

  • Private

    Your JSON never leaves your device. No upload, no sign-up.

  • Open and save files

    Load a .json file and download the formatted result.

Frequently asked questions

What does a JSON formatter do?

A JSON formatter (or beautifier) adds line breaks and indentation to JSON so it is easy to read. This tool also validates the JSON and can minify it back to a single line.

How do I find the error in my JSON?

Paste your JSON and the tool shows 'Invalid JSON' with the line and column of the first problem. Common causes are a missing comma, a trailing comma, single quotes instead of double quotes, or keys without quotes.

Is my JSON uploaded to a server?

No. Formatting and validation happen entirely in your browser, so private data such as API responses or config files stays on your device.

What is the difference between formatting and minifying JSON?

Formatting adds spaces and line breaks to make JSON readable. Minifying removes them to make the file as small as possible, which is useful for APIs and storage. The data itself stays the same.

Can I format large JSON files?

Yes. Files of several megabytes work fine; the limit is your device's memory. Use Open file to load a .json file directly.

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