A JSON formatter is a free online tool that takes compact or messy JSON and pretty-prints it with clean indentation and color-coded syntax highlighting, so you can actually read it. Paste an API response or config file, pick your indent style, and get readable, highlighted JSON instantly.
Your formatted JSON will appear here...How do I format JSON online?
Paste your JSON into the input box, choose 2-space, 4-space, or tab indentation, and press Format. The pretty-printed result appears below with syntax highlighting. If the JSON is invalid, you get an error pointing at the exact position of the problem.
Formatting (also called beautifying or pretty-printing) adds line breaks and indentation without changing the data, which makes API responses, config files, and logs far easier to read and debug. The original structure, key order, and values are preserved exactly.
What do JSON syntax errors like "Unexpected token" mean?
They mean the text is not valid JSON. The usual culprits are trailing commas, single quotes instead of double quotes, unquoted keys, or comments. This tool reports the character position, line, and column so you can jump straight to the mistake.
JSON is stricter than JavaScript object literals: keys must be double-quoted, the last item in an object or array cannot have a trailing comma, and comments are not allowed. Use the JSON validator on this site for detailed fix hints when a file refuses to parse.
Frequently asked questions
Is this JSON formatter free?
Yes. Format unlimited JSON documents with no account and no limits. It runs entirely in your browser.
Can I choose the indentation style?
Yes. Pick 2 spaces, 4 spaces, or a tab character. The formatted output and the copy button both use your choice.
Does formatting change my data?
No. Formatting only changes whitespace and line breaks. Key order, values, and structure stay exactly the same.
Why is my JSON invalid?
Common causes: trailing commas, single-quoted strings, unquoted keys, comments, or a missing bracket. The error message shows the exact position so you can fix it quickly.
Is my JSON sent to a server?
No. Parsing and formatting happen locally with your browser JavaScript engine. Your data never leaves your device.