JSON Validator

JSON Validation vs Formatting

• Validation tells you if JSON is syntactically correct (parseable by any JSON parser)
• Formatting makes valid JSON readable (adds indentation, line breaks)
• Schema validation checks if JSON matches a defined structure (e.g. all required fields present, correct types)

This tool covers the first two. For pretty-printing and visualising nested structure, use the JSON Formatter.

What Makes JSON Invalid?

The most common causes of invalid JSON:

1. Trailing commas — {"a": 1,} is invalid; JavaScript allows it, JSON does not
2. Single quotes — JSON requires double quotes: "key" not 'key'
3. Unquoted keys — {a: 1} is JavaScript notation, not JSON
4. Comments — JSON does not support // or /* */ comments
5. Undefined/NaN/Infinity — these JavaScript values are not valid JSON

Validating JSON in Production

If you're receiving JSON from an external API or webhook, always validate it before processing. Unexpected null values or missing fields cause silent failures in automation workflows — Make.com Error Handling covers exactly this kind of data validation as a first line of defence. Book a session if you're building a production API integration and want it done right.