JSON Formatter & Validator

How it works

JSON is unforgiving: a single trailing comma or single-quoted string makes the whole document unusable, and most parsers just say no. This tool parses your input with the browser's built-in JSON parser, the same strict engine web APIs use. In format mode it re-prints the parsed value with your chosen indentation (2 spaces, 4 spaces or tabs), which normalizes messy payloads into something a human can read and diff. Minify mode strips all insignificant whitespace for production payloads and config files. Validate mode checks syntax only and reports either success or the parser's error, which typically names the character position of the first problem, a missing comma, an unquoted key, or a bracket mismatch are the usual culprits. The round trip through the parser guarantees the output is semantically identical to the input: key order is preserved, numbers and strings are untouched, and duplicate keys keep the last value, matching how virtually all JSON consumers behave. Because everything runs locally, the tool is safe for API responses, tokens and configuration files that should never be pasted into a remote service.