ThoseBoringTools
💻 Developer Tools

JSON Formatter & Validator

Paste any JSON below to pretty-print it with proper indentation, minify it to a single line, or check it for syntax errors. Nothing is sent to a server — formatting happens entirely in your browser.

How to use this tool

  1. 1Paste or type your JSON into the input box.
  2. 2Click "Format" to pretty-print it with indentation, or "Minify" to compress it to one line.
  3. 3If the JSON is invalid, an error message will show exactly what's wrong and where.

Frequently asked questions

Is my JSON data uploaded anywhere?
No. This formatter runs entirely in your browser using JavaScript's built-in JSON parser. Your data never leaves your device.
Why does it say my JSON is invalid?
Common causes are trailing commas, single quotes instead of double quotes, unescaped strings, or missing brackets. The error message includes the position where parsing failed.
What's the difference between formatting and minifying?
Formatting adds indentation and line breaks so JSON is easy to read. Minifying removes all unnecessary whitespace to make the payload as small as possible.

Related tools