JSON Formatter
Paste minified or messy JSON and get a clean, indented, readable version instantly.
Processed locally in your browser. Nothing you enter is uploaded or stored.
Overview
A JSON formatter re-indents and line-breaks JSON so nested objects and arrays are easy to scan — useful when you're debugging an API response or reading a minified config file.
How to use it
- 1Paste or type your JSON into the input panel.
- 2Choose an indent size (2 or 4 spaces, or tabs).
- 3Click Format — the output panel updates instantly.
- 4Copy the result or download it as a .json file.
How it works
The formatter parses your input with the browser's native JSON parser, then re-serializes it with the indentation you choose. Because it uses a real parser, invalid JSON is caught immediately with a precise error location.
Examples
Minified to formatted
Input
{"id":1,"name":"Ada","active":true}
Output
{ "id": 1, "name": "Ada", "active": true }
Tips
- Trailing commas and single quotes aren't valid JSON — use the JSON Validator to see exactly where parsing fails.
- Large payloads (multi-MB) format fine since everything happens in-memory in your browser.