JSON Formatter & Validator
Paste any JSON and this tool instantly validates it, pretty-prints it with your choice of indentation, or minifies it down to the smallest possible size — with clear error messages if something is wrong.
How it works
Paste or type JSON into the input box. It's validated as you type using your browser's built-in JSON parser. Switch between "Pretty" (with your chosen indentation) and "Minify" to see the formatted result, and use the copy button to grab it.
Tip
Minifying removes all unnecessary whitespace, which is useful for reducing the size of JSON sent over a network — compare the byte sizes shown below the output to see the difference.
Why does it say my JSON is invalid?
Common issues are trailing commas, single quotes instead of double quotes, or missing quotes around property names — none of these are valid in standard JSON. The error message points to roughly where the parser got stuck.
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