JSON Formatter
Format and validate JSON.
Input
Result
What is a JSON Formatter?
A JSON Formatter is a free online tool that formats (pretty-prints) and validates JSON data. It adds proper indentation, line breaks, and syntax highlighting to raw JSON, making it human-readable. It also detects syntax errors and can minify JSON for production use.
How to format JSON manually
Manual JSON formatting follows a simple indentation rule: each nested object or array is indented by 2 or 4 spaces. Opening braces and brackets start a new level, and closing braces return to the previous level. Each key-value pair goes on its own line, with a colon separating the key and value.
Example calculation
Raw JSON: {"name":"John","age":30,"address":{"city":"NYC","zip":10001}} becomes formatted JSON with each property on its own line, nested objects indented, and consistent spacing around colons and commas.
Common mistakes
- Trailing commas — JSON does not allow trailing commas after the last item in an object or array. Remove the comma after the final property.
- Using single quotes — JSON requires double quotes for all strings and property names. Single quotes are not valid in JSON.
- Missing quotes on keys — In JSON, all object keys must be enclosed in double quotes. Unquoted keys are valid in JavaScript but not in strict JSON.
Frequently asked questions
What is a JSON Formatter?
A JSON Formatter is a tool that formats (pretty-prints) and validates JSON data, making it easier to read by adding proper indentation and line breaks.
How do I validate JSON?
Paste your JSON into the input area and click Format. The tool will parse your JSON and report any syntax errors. Valid JSON will be displayed with proper formatting.
What makes JSON invalid?
Common JSON errors include trailing commas, missing quotes around keys, using single quotes instead of double quotes, mismatched brackets, and missing colons between keys and values.
Can I minify JSON with this tool?
Yes, the tool can both format and minify JSON. Minified JSON removes all whitespace and line breaks, which is useful for reducing file size in production.
What is JSON used for?
JSON (JavaScript Object Notation) is a lightweight data interchange format used for API communication, configuration files, data storage, and transmitting data between servers and web applications.