What is JSON Validation?
JSON (JavaScript Object Notation) validation checks whether a string is valid JSON according to the RFC 8259 specification. Valid JSON must have properly matched braces, quoted string keys, and correct value types.
Common JSON Errors
The most frequent JSON syntax errors include:
- Trailing commas after the last element:
{"a": 1,} - Single quotes instead of double:
{'key': 'value'} - Unquoted keys:
{key: "value"} - Missing commas between elements:
{"a": 1 "b": 2} - Comments in JSON:
{"a": 1 // comment}
JSON Validation API
Validate JSON programmatically with our free API:
curl -X POST /api/json/validate \
-H "Content-Type: application/json" \
-d '{"json": "{\"valid\": true}"}'
Returns: {"valid": true, "formatted": "..."} or {"valid": false, "error": "...", "line": 3}
Related Tools
JSON Formatter | JSON to YAML | JSON to CSV | JSONPath Tester