What is JSON Formatter?
A JSON formatter parses a JSON document and prints it again with consistent two-space indentation. Because the text must parse first, formatting also confirms the document is valid; if it is not, the parser's error message points to where it stopped.
How to use JSON Formatter
- Paste your input into the editor above, or select Sample to load an example.
- Select Format & validate. If the input cannot be processed, a message explains what to fix.
- Use Copy or Download to take the result with you, and Clear to start again.
Example
Input
{"name":"John","age":30}Output
{
"name": "John",
"age": 30
}Practical use cases
- Review API responses
- Debug configuration files
- Prepare readable examples for documentation
Common problems
- Using single quotes instead of JSON double quotes
- Leaving a trailing comma
- Forgetting to quote property names
Frequently asked questions
Does formatting change my data?
No. Only whitespace changes. Keys, values, and array order are preserved, although duplicate keys collapse to the last value because that is how JSON.parse behaves.
Why does my JSON fail to format?
The most common causes are single quotes, trailing commas, unquoted keys, and comments. None of these are allowed in standard JSON.
Is JSON Formatter & Validator free to use?
Yes. JSON Formatter & Validator is free and does not require an account.
Does my input leave the browser?
No. This tool performs its processing locally in your browser and does not need to upload your input.