JSON Formatter

Paste your JSON, choose an indent size of 2, 4 or 8 spaces, then press Run. The input is parsed first, and only if it is valid do you get a formatted result. Two outputs are returned together: the pretty-printed document using your chosen indent, and a minified copy with all unnecessary whitespace removed.

Invalid JSON fails with a readable description. The underlying parser message — which typically starts with something like "Syntax error" — is trimmed down to the part that helps you, so you are told the input is malformed or empty rather than being handed raw engine output. Empty input is caught separately with its own message.

Because the document has to parse before anything is formatted, this doubles as a JSON validator. Trailing commas, single quotes, unquoted keys, comments and truncated objects are all rejected, which makes it quick to find the stray character that broke a large payload.

Two spaces is the common default and the most compact readable form. Four spaces is easier to scan in deeply nested structures and matches many style guides. Eight spaces is useful when a document has been minified and you want the structure made obvious while you read it, for example during a debugging session.

Nothing is written to storage, and there is no account to create. JSON often contains tokens, keys or personal data, so treating formatting as a local convenience rather than a service you upload to keeps that data out of anyone else's logs. Reset the form and the text is gone from the page.