JSON Formatter
Paste messy or minified JSON and get clean, validated, indented output. Format, minify, and catch syntax errors instantly — everything runs in your browser, nothing is uploaded.
About JSON Formatter
A JSON formatter takes minified or messily-indented JSON and re-prints it with consistent indentation so it's readable, while validating that it's syntactically correct. This one parses your input with the browser's native JSON engine, so if it formats, it's valid — and if it doesn't, you get the exact parser error. Nothing is sent to a server; the whole thing runs locally on your machine.
Frequently asked questions
Is my JSON uploaded anywhere?+
No. Formatting happens entirely in your browser with the built-in JSON parser. Your data never leaves your device, which makes it safe for pasting config or API responses.
What does 'minify' do?+
Minify strips all whitespace and newlines to produce the smallest valid JSON on a single line — handy for embedding in a query string or trimming payload size.
Why does it say my JSON is invalid?+
Common causes are trailing commas, single quotes instead of double quotes, unquoted keys, or a stray comment — none of which are valid JSON. The error message points at the position where parsing failed.