JSON Formatter & Validator
Paste messy or minified JSON and get clean, indented output you can actually read. The tool validates as you go and points to the exact character where parsing failed.
How to use json formatter & validator
- Paste your JSON
Drop raw or minified JSON into the input box. Data from an API response works well.
- Format or minify
Choose an indent size and click Format for a readable tree, or Minify to strip whitespace.
- Copy the result
If the JSON is valid you'll see it below — copy it with one click. Errors show the exact position.
Features
Invalid JSON is caught instantly with the position of the problem so you can fix it fast.
Switch between human-readable indentation and compact single-line output.
Parsing happens in your browser with the native JSON engine — your data never leaves the page.
Frequently asked questions
Is my JSON sent to a server?
No. Formatting and validation run entirely in your browser using JavaScript's built-in JSON parser.
Why does it say my JSON is invalid?
Common causes are trailing commas, single quotes instead of double quotes, or unquoted keys. The status message points to the character that failed.
How large a file can I format?
It handles typical API payloads comfortably. Very large files (tens of MB) may be slow because everything runs on your device.