About this tool
Paste JSON from an API response, config file or log and format it with readable indentation, compress it to a single line, or check that it is valid. If the JSON is broken, the error message tells you what went wrong.
How to use it
- Paste JSON into the input box.
- Choose Format (2 or 4 spaces) or Minify.
- Fix any reported error, then copy the result.
Good to know
- Validation uses the browser's built-in JSON parser, so it follows the official JSON standard.
- Comments and trailing commas are not valid JSON and will be reported as errors.
- Nothing you paste is sent to a server.
Frequently asked questions
Why does my JSON show an error?
Common causes are single quotes instead of double quotes, trailing commas, or unquoted keys.
Is it safe for private data?
Yes. Formatting runs locally in your browser and the data never leaves your device.