JSON Formatter
Validate and pretty-print JSON.
Runs in your browser. Your file is never uploaded.
How to use JSON Formatter
- 1Paste JSON or open a file.
- 2Choose the indent, or Minify.
- 3Copy or download the result. Errors show the exact line and column.
Questions
Is my JSON sent anywhere?
No. It's formatted in this page as you type. That's worth knowing for JSON containing API keys or customer data, which many online formatters upload.
Why is my JSON invalid?
Common causes are a trailing comma after the last item, single quotes instead of double quotes, unquoted keys, and comments, none of which JSON allows. The error message points to where parsing stopped.
Are my files uploaded anywhere?
No. The tool runs as code in your browser tab and processes the file on your own device. Nothing is sent to a server, and the site's security policy blocks the page from sending data to any other website. You can check: open your browser's developer tools, watch the Network tab while the tool runs, and you'll see no upload.