JSON to Avro Schema Converter

Generate a draft Avro schema (.avsc) from sample JSON. Runs locally in your browser.

JSON

Avro Schema

{
  "type": "record",
  "name": "Root",
  "fields": [
    {
      "name": "orderId",
      "type": "string"
    },
    {
      "name": "customer",
      "type": {
        "type": "record",
        "name": "Customer",
        "fields": [
          {
            "name": "name",
            "type": "string"
          },
          {
            "name": "email",
            "type": "string"
          }
        ]
      }
    },
    {
      "name": "items",
      "type": {
        "type": "array",
        "items": {
          "type": "record",
          "name": "Item",
          "fields": [
            {
              "name": "sku",
              "type": "string"
            },
            {
              "name": "quantity",
              "type": "int"
            },
            {
              "name": "unitPriceCents",
              "type": "int"
            }
          ]
        }
      }
    },
    {
      "name": "status",
      "type": "string"
    }
  ]
}
​

The Kafka IDE

Register and evolve Avro schemas in Kafma

Kafma is a desktop app for Kafka. Register schemas, compare version changes, and publish updates with Schema Registry compatibility checks.

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Kafma drafting a new Avro version of orders.created-value with a live diff and compatibility set to BACKWARD
Kafka Schema Explorer

JSON to Avro FAQ

Why does the schema contain unions or nullable fields?
Mixed array values such as [1, "a"] produce a union of int and string. A field present in only some array objects becomes nullable with a null default. Compatible numeric types are combined into a wider type.
Why did "1999" stay string in the Avro schema?
Quoted digit strings stay string. Unquoted integers that fit signed 32-bit become int; larger safe integers become long. If a quoted value should be numeric, copy the schema into your editor or Kafma and adjust its type.
Why is a JSON key missing from the Avro schema?
Fields containing only null or empty arrays are omitted because their types cannot be inferred. Provide a concrete sample value and convert again.
Why is the root record named Root?
The converter uses Root as a placeholder name. Copy the schema into your editor or Kafma, then rename it before registering.
How do I use this schema with Kafka?
Review the inferred field types and names, then register the schema in Kafka Schema Explorer. Use the registered schema to generate and serialize a payload in Kafka Console and produce it to a topic.
Is my input uploaded?
No. Conversion runs in your browser. Your input and generated output are not uploaded.
Can I generate sample JSON from an Avro schema?
Use the Avro to JSON converter to generate sample JSON from an Avro schema.