One misplaced comma makes a whole JSON file invalid, and the program that reads it simply fails. A validator tells you what is wrong and where.
How to validate
- Open JSON Validator and paste your JSON.
- Read the result: valid, or the error with its line and column.
- Fix the problem and check again.
Most common mistakes
- Trailing comma after the last item.
- Single quotes instead of double quotes.
- Keys without quotes.
- Comments, which JSON does not allow.
- A missing closing bracket or brace.
Valid does not mean right
A validator checks the syntax only. It cannot tell whether the field names and values are what your application expects.
Frequently asked questions
Is my data uploaded?
No. Everything runs in your browser, so what you type never leaves your device.
Ready to start?
Open JSON Validator