JSON Prettifier Tool

Format, validate, and minify JSON live as you type, with the exact parser error if it's invalid.

100% private, runs in your browser

JSON input

Indent

{
  "name": "Bytelify",
  "tools": 210,
  "active": true
}

Formatted live as you type, entirely in your browser. Invalid JSON shows the parser's exact error message so you can find the problem quickly.

What is JSON Prettifier Tool?

Paste minified or messy JSON and get it formatted with proper indentation instantly, choose 2 spaces, 4 spaces, or tabs. If the JSON is invalid, you get the exact parser error message (what's wrong and roughly where) instead of a generic "invalid JSON" message, so you can fix it faster. A minify button is also included for the opposite direction: squeeze formatted JSON down to a single compact line. Everything happens in your browser; nothing you paste is sent anywhere.

FAQ

Yes. If the input isn't valid JSON, no formatted output is shown, and you get the JavaScript parser's actual error message so you can locate the problem.

No hard limit set by the tool. Very large JSON (multiple megabytes) may feel slower since parsing happens in your browser's main thread, but typical API responses and config files format instantly.

Yes, use the "Minify input" button, it re-parses your current input and replaces it with the compact, single-line form.