All tools
JSON Formatter
Beautify, minify and validate JSON.
Everything here runs entirely in your browser. Nothing you type, paste, or upload is ever sent to a server, logged, or stored.
About the JSON Formatter
Formats JSON with consistent indentation, minifies it back down, and validates it — pointing at the position of the first syntax error rather than only refusing the input.
When you would use it
- Making an unreadable single-line API response legible.
- Finding the trailing comma or unquoted key that is breaking a parse.
- Minifying a config file before pasting it somewhere size-constrained.
What it does not tell you
Valid JSON is not correct data: this checks the syntax, never whether the fields are the ones something expects. Very large numbers lose precision when parsed, because JSON numbers become floating-point values. Everything is processed in your browser.