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Handy Browser Tools

JSON Formatter

Paste or type JSON below to pretty-print and validate it. Choose your indentation, then copy or download the formatted result. Invalid JSON shows the exact parse error.

How to use
Private by default: processing stays on your device
YOUR JSON

Paste or type JSON to format

Clean JSON, instantly.

Validates as you type; formats on demand for large inputs.

Formatted output

Good to know

Large integers are preserved exactly — what you paste is what you get. Formatting runs entirely in your browser.

How to use this tool

  1. Paste your JSON into the input box.
  2. Choose indentation and select Format; smaller inputs also update automatically.
  3. Fix any reported JSON error, then copy or download the formatted output.

Example: minified JSON → formatted

Input

{"name":"Ada","languages":["js","py"],"active":true}

Output

{
  "name": "Ada",
  "languages": [
    "js",
    "py"
  ],
  "active": true
}
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Frequently asked questions

Is my JSON uploaded to a server?

No. Formatting runs entirely in your browser with JavaScript, so your JSON never leaves this device. A draft is saved in this browser's local storage so it's restored if you return, and it stays on this device. Avoid pasting sensitive content on shared devices, and note that a share link made with "include my text" contains your JSON and exposes it to anyone who receives the link.

Does this tool validate JSON too?

Yes. If your input isn't valid JSON, you'll see the exact parse error so you can find and fix the problem quickly.

What indentation options are supported?

You can format with 2 spaces (default), 4 spaces, or tabs. Use the JSON Minifier tool if you want to compress instead.

Is there a size limit?

Inputs under 50,000 characters update automatically as you type. Larger inputs need the Format button to update the result, and very large inputs are limited by your browser's memory.

Related tools

JSON Minifier

Minify JSON online by removing all whitespace and line breaks.

JSON Compare

Compare two JSON documents free in your browser.