JSON Formatter
Format, validate, and minify JSON with clear error messages.
How to use JSON Formatter
- Paste your JSON into the input box.
- Click Format to pretty-print it, or Minify to compact it to one line.
- If the JSON is invalid, an error message shows exactly which line and column the problem is on.
- Use the copy button to copy the formatted result.
About this tool
The JSON Formatter pretty-prints messy or minified JSON with your choice of indentation, validates it and points to exactly where a syntax error is if it's invalid, and can also minify formatted JSON down to a single compact line. All processing runs instantly in your browser — nothing is uploaded or sent to a server, so it's safe to paste JSON containing sensitive data.
Frequently Asked Questions
Is my JSON data uploaded anywhere?
No — formatting and validation both happen entirely in your browser using JavaScript's built-in JSON parser. Nothing you paste is sent to a server, so it's safe to use with sensitive or private data.
Why does it say my JSON is invalid?
Common causes are trailing commas (not allowed in standard JSON), single quotes instead of double quotes, unquoted keys, or a missing closing bracket or brace. The error message shows the exact line and column where parsing failed.
What's the difference between formatting and minifying?
Formatting adds indentation and line breaks to make JSON easier to read. Minifying removes all unnecessary whitespace to make the file as small as possible — useful before sending JSON over a network.