JSON Validator
Check if your JSON is valid before using it in APIs, configs, or code. Get clear error messages with context to fix issues quickly.
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100% Private. Your JSON is validated entirely in your browser. No data is ever sent to any server.
Input
0 chars
Result
Ctrl/Cmd + Enter to validate
How to Validate JSON
- Paste your JSON into the input editor.
- Click Validate or press
Ctrl+Enter. - The tool will show whether your JSON is valid or display the specific error with context.
- Fix any reported issues and validate again.
Common Validation Results
Valid JSON
{"name": "Alice", "age": 30, "active": true}Returns: Valid JSON
Missing Comma
{"name": "Alice" "age": 30}Returns: Syntax error pointing to the missing comma.
Trailing Comma
{"name": "Alice", "age": 30,}Returns: Unexpected token error at the trailing comma.
Limitations
- Syntax validation only — Checks for valid JSON structure, not semantic correctness or data types.
- No JSON Schema support — Cannot validate against a schema. Use a dedicated schema validator for that.
- No file upload — Paste JSON directly. For large files, use the JSON Minifier first to reduce size.
- Large file warning — Files over 50MB may slow your browser during validation.
Frequently Asked Questions
What JSON errors can this tool detect?
It catches all syntax errors: missing commas, unclosed brackets, invalid strings, trailing commas, comments in JSON, single quotes, and any other violation of the JSON specification.
Does it check JSON structure or just syntax?
It validates JSON syntax using the browser native JSON.parse(). It does not validate against a JSON Schema. For schema validation, use a dedicated JSON Schema validator.
Is my data private?
Yes. All validation happens in your browser. Your JSON data is never sent to any server.