How to Validate JSON Online
JSON is used everywhere: APIs, configs, data exchange. Invalid syntax (missing comma, wrong quote, trailing comma) causes parsing errors. Our JSON Validator shows the exact line and message so you can fix it fast.
Common causes
- Missing or extra comma between elements.
- Unclosed bracket or brace.
- Trailing comma after the last element (not allowed in strict JSON).
- Single quotes instead of double quotes for strings.
How to fix
- Paste your JSON into the validator and run the check.
- Fix the reported line; often one fix resolves several errors.
- Use Format to auto-indent and spot structural issues.
Use our tool
Open JSON Validator