JSON Formatter
Format, validate, and minify JSON data
Input
Output
What it does: Format, validate, and minify JSON data. This free online tool works entirely in your browser with no installation required.
How to use:
- Copy your raw JSON data and paste it into the left input panel.
- Click Format to beautify with indentation, or Minify to compress into a single line.
- Review the validation status and copy the output with one click.
Privacy: All processing happens in your browser. No data sent to servers.
Best for: Anyone who needs quick JSON Formatter without installing software.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write and easy for machines to parse and generate. It is widely used in web APIs, configuration files, and data storage. JSON represents data as key-value pairs organized in objects ({}) and arrays ([]).
Common JSON Errors to Watch For
- Trailing commas — JSON does not allow trailing commas after the last item in an object or array. Remove the comma after the final value.
- Unquoted keys — All object keys must be wrapped in double quotes. Single quotes or bare identifiers are invalid in JSON.
- Missing quotes around strings — String values must be enclosed in double quotes. Unquoted text like
hellowill cause a parse error. - Nested quotes — Use backslash escaping (
\") for quotes inside strings to avoid breaking the structure. - Comments — JSON does not support comments. Unlike JavaScript objects, you cannot use
//or/* */in JSON files.
Best Practices for JSON
- Always validate your JSON before using it in production applications to catch syntax errors early.
- Use meaningful, consistent key names following a naming convention such as camelCase or snake_case.
- Keep deeply nested structures to a minimum — excessive nesting makes JSON hard to read and process.
- Use JSON Schema to define the expected structure of your data for automatic validation.