JSON Formatter & Validator
Validate JSON, format it for reading, or minify it.
● Processed locally in your browser unless the page says otherwise.
What JSON formatting and validation checks
This JSON formatter and validator checks whether JSON is valid and turns minified JSON into a readable structure. It is useful for API responses, config files, test data, frontend-backend communication, and debugging.
JSON is strict about punctuation. Common errors include missing commas, extra trailing commas, single quotes, unquoted keys, unmatched brackets, and wrong value types.
Formula or logic
- Objects use { }
- Arrays use [ ]
- Keys must use double quotes
- Strings must use double quotes, not single quotes
- Trailing commas are not valid JSON
Example
If an API returns a long minified JSON string, format it to inspect the field hierarchy. If the JSON is invalid, the validation message can help locate the issue.
Common questions
Can JSON include comments?
Standard JSON does not support comments. Some tools use JSONC or other formats when comments are needed.
Can JSON use single quotes?
No. Standard JSON requires double quotes for strings and keys.
Does formatting change the data?
Normal formatting changes whitespace and indentation, not the actual data values.