JSON Formatter & Validator

How it works

This tool parses your input with the browser's native JSON parser. Format re-serializes it with readable indentation; Minify strips all non-essential whitespace. If the input isn't valid JSON, you'll see the parser's exact error (e.g. a trailing comma or an unquoted key) instead of a silent failure. Nothing you paste here is sent to a server — parsing happens entirely in your browser.

Common JSON mistakes this catches

• Trailing commas after the last item in an object or array (valid in JS, invalid in JSON).
• Unquoted or single-quoted object keys.
• Using undefined or a bare function instead of null or a string.
• Comments (JSON has no comment syntax, unlike JSON5 or JSONC).