Protobuf Schema Validator

Check syntax, field definitions, and type references in a Protobuf schema (.proto). Runs locally in your browser.

Protobuf Schema

The Kafka IDE

Register and evolve Protobuf 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 Protobuf version of orders.confirmed-value with a live diff and compatibility set to BACKWARD
Kafka Schema Explorer

Protobuf Schema Validator FAQ

Does this validate a JSON payload against the schema?
No. This validator checks the schema definition itself. To validate a JSON payload against a registered schema, use the Kafka Schema Explorer.
Does this check Schema Registry compatibility?
No. This validator checks one schema in isolation. It does not compare the schema with earlier versions or apply a subject's compatibility mode. Use the Kafka Schema Explorer to publish schemas with Schema Registry compatibility checks.
Why is a Protobuf import missing or a type unknown?
This validator supports Google well-known imports, but it does not load custom .proto files or Schema Registry references. For a standalone check, inline the required definitions and update package-qualified type names. Use the Kafka Schema Explorer when the schema depends on registered references.
Is my input uploaded?
No. Validation runs in your browser. Your input is not uploaded.
Can I generate sample JSON from a .proto schema?
Use the Proto to JSON converter to generate sample JSON from a .proto schema.
Can I generate a .proto schema from sample JSON?
Use the JSON to Proto converter to infer a .proto schema from sample JSON.