Beautify, minify, and validate your JSON
Paste JSON and get it back beautified with consistent indentation, syntax highlighting, and a collapsible tree view — or minified to a single line for compact storage. The formatter also validates as it parses, pointing you at the first syntax error instead of a silent failure.
Formatting happens locally in your browser, so API responses, config files, and payloads containing sensitive data never leave your machine.
Paste {"user":{"id":42,"name":"Ada","roles":["admin","dev"]}} and format it. You get each key on its own line with two-space indentation, and the tree view lets you collapse the roles array. If you had typed a trailing comma after "dev", the validator would flag it — trailing commas are legal in JavaScript but not in JSON, and they are the single most common reason a payload that "looks fine" fails to parse.
JSON is stricter than JavaScript object literals: keys must be double-quoted, strings must use double quotes, and trailing commas, comments, and undefined are all forbidden. The validator applies the real JSON spec, which is what servers and parsers enforce.
The formatter runs entirely in your browser — nothing is transmitted or stored. That said, treat any pasted secret with normal care: this page doesn't keep it, but your clipboard history might.
Beautify adds line breaks and indentation for human reading. Minify strips all insignificant whitespace to produce the smallest equivalent document — same data, different formatting. Round-tripping between them never changes the content.
Yes, within browser memory limits — documents of several megabytes format fine. For very large files (hundreds of MB), a command-line tool like jq is the better fit.