JSON Validator Online
Check if your JSON is valid, get error messages with line numbers, and auto-fix common issues.
Try this invalid JSON to see error detection:
{ "name": "test", "items": [1, 2, 3,] }Common JSON Errors
Trailing commas- Remove comma before } or ]Single quotes- JSON requires double quotesUnquoted keys- All keys must be in double quotesComments- JSON does not support commentsUndefined- Use null instead of undefined
Valid JSON Types
String- "hello"Number- 42, 3.14, -1Boolean- true, falseNull- nullArray- [1, 2, 3]Object- {"key": "value"}
Why Validate JSON?
Invalid JSON can break APIs, crash applications, and cause silent data loss. Validating JSON before deployment catches syntax errors early, saving hours of debugging. Our validator pinpoints the exact line and column of each error.
How to Validate JSON Online
Paste your JSON into the editor and click "Validate". If there are errors, you'll see the exact position and a description of what's wrong. Click "Auto-Fix" to automatically repair common issues like trailing commas and single quotes.
JSON Linting vs Validation
JSON validation checks whether data follows the JSON specification (RFC 8259). JSON linting goes further by checking style and formatting. Our tool does both — it validates syntax and can auto-fix style issues to produce clean, standards-compliant JSON.
Common Use Cases for JSON Validation
- Pre-deployment checks – Validate config files before pushing to production to prevent runtime crashes
- API development – Ensure request and response payloads are valid JSON before integration testing
- Data import/export – Check JSON dumps from databases or third-party services before processing
- Manual JSON editing – Catch typos and syntax errors when hand-editing JSON configuration
- CI/CD pipelines – Validate JSON artifacts as part of automated build and deployment workflows