JSON Formatter

Pretty-print, minify, validate and explore JSON in a collapsible tree — 100% in your browser.

JSON's grammar is small and completely unforgiving. Trailing commas, single-quoted strings, comments, NaN and Infinity are all things people write and none of them are valid JSON, which is why a parse error is usually a typo three lines above where the error points. Formatting a document is really a proof that it parsed at all.

Minifying matters more than it looks on an API payload: whitespace in a deeply nested response can be a third of the bytes on the wire, and it compresses well but still costs parse time on a phone. Pretty-printing is the opposite trade, for when a human has to read it.

A collapsible tree earns its keep on responses you did not design — a webhook body or a third-party API where you are hunting for one field and do not yet know how deep it lives.