What this tool does
The JSON formatter helps quickly check data structure, make a document readable, or compress it for transfer.
How to use
- Paste JSON into the input field.
- Choose indentation and run formatting or minification.
- Copy the finished result.
Strict JSON validation
The formatter uses the browser's standard JSON parser. If the document cannot be parsed, the tool shows an error and does not produce output, so you do not copy broken data into code, an API request, or a configuration file.
JSON requires double quotes around strings and keys. It does not support comments, single quotes, or a trailing comma after the last object or array item. If data comes from JavaScript or JSON5, convert it to strict JSON first.
Formatting and minifying
Format mode makes the structure readable with 2-space or 4-space indentation. It is useful for inspecting API responses, settings, logs, test data, and nested objects where you need to see levels and keys quickly.
Minify mode removes unnecessary spaces and line breaks while keeping valid JSON. The compact version is useful for transport, one-line fields, or checking how much space is saved.
Working safely
The tool does not repair meaning or guess missing brackets. It parses the input JSON and serializes it again with the browser serializer, so whitespace changes while strings and numbers remain valid JSON values.
Before replacing a production file or value, keep the original and test the result in the system that will use it. For very large documents, speed depends on your device memory and browser performance.