JSON Formatter & Validator

About this JSON formatter

This is a free JSON formatter, validator and beautifier. Paste your JSON and click Beautify to format it with clean indentation, or Minify to strip whitespace for production. If the JSON is invalid, you get a clear error message showing what went wrong. Everything runs in your browser, so your data stays private.

Beautify vs minify

Beautify adds indentation and line breaks so JSON is easy to read and debug. Minify removes every unnecessary space so the file is as small as possible, which is what you want in production and API responses.

Common reasons JSON is invalid

• A trailing comma after the last item in an object or array.
• Single quotes instead of double quotes around keys or strings.
• Keys that are not wrapped in double quotes.
• Comments, which standard JSON does not allow.

Frequently asked questions

How do I validate JSON?

Paste it into the box. The status line tells you instantly whether it is valid, and shows the exact error if it is not.

Why is my JSON invalid?

The most common causes are trailing commas, single quotes instead of double quotes, unquoted keys, and comments. The error message points to where the problem is.

Is my data sent to a server?

No. The formatting and validation happen entirely in your browser, so your JSON never leaves your device.