JSON formatter & validator
Check the syntax, then choose readable or compact output.
JSON input
UTF-8, up to 1 MB.
Result
No result yet. Paste JSON, choose an action and select Process JSON.
What each action does
Validate only checks the syntax and leaves the text unchanged.Pretty-print rewrites it with two spaces of indentation. Minify removes insignificant whitespace. Valid output can be copied or downloaded as a .json file.
Example
Example input
{"name":"Ada","tags":["math","code"]} is an object with two keys. Pretty-print puts each key and array item on its own line.
Errors and number handling
Syntax errors include a line and column when the browser reports a position. The tool does not run JavaScript, fetch schemas or follow $ref links. JavaScript numbers cannot keep every digit beyond 15 significant digits: this tool warns about long decimals and numbers too small to represent, and rejects integers outside ±9,007,199,254,740,991 rather than rounding them silently. Duplicate object keys follow the JSON parser’s usual last-value-wins rule.
Limits and privacy
Pasted text or a UTF-8 .json file up to 1 MB. Processing happens in this tab; the input, output and filenames are not sent to a server or added to analytics. Extra indentation changes whitespace only, not the parsed values.