How to use the JSON formatter
Paste any JSON into the input box and press Format to pretty-print it with your chosen indent (two spaces, four spaces, or a tab). Press Minify to compress it into a single compact line. Ticking Sort keys re-orders every object's keys alphabetically before output, which is handy when you want a stable, diff-friendly representation of an API payload.
The tool validates as it works. If your JSON is malformed — a trailing comma, an unclosed brace, a lone quote — the formatter reports the error and, when the parser can locate it, the exact line where it broke. This makes fixing large configuration files and API responses much faster than reading a vague "unexpected token" message.
Because all processing happens locally in JavaScript, your data never leaves the page. There is no server round-trip, no account, and no upload. That makes it safe to paste internal or sensitive payloads when debugging.
Common JSON mistakes this tool catches
- Trailing commas after the last element of an object or array.
- Single-quoted strings or unquoted keys.
- Unescaped control characters or newlines inside strings.
- Comments, which standard JSON does not allow.
More developer tools
DevStamp is a small suite of free, in-browser utilities: