Understanding JSON Schema Validation

JSON is flexible, which is both its greatest strength and its biggest weakness. Without a rigid structure, APIs can easily break when an expected field is missing or comes in the wrong type.

What is JSON Schema?

JSON Schema is a vocabulary that allows you to annotate and validate JSON documents. Think of it as a contract for your data. It answers questions like:

• Is userId a number or a string?
• Is the tags array optional?
• Does email look like a valid email address?

Basic Example

{
  "type": "object",
  "properties": {
    "name": { "type": "string" },
    "age": { "type": "integer", "minimum": 0 }
  },
  "required": ["name"]
}

Why Use It?

Implementing schema validation at your API gateway ensures that malformed data never reaches your core business logic, preventing "undefined is not a function" errors deep in your stack. Try our JSON to Schema Generator to automatically create schemas from your JSON data.