Avro & Protobuf Schema Inspector
Paste an .avsc or .proto file and see fields, types, and structure.
Schemas parsed locally — nothing leaves your deviceInspect and visualize Avro and Protobuf schemas
About this schema inspector
Paste an Avro schema (JSON .avsc) or a Protobuf definition (.proto) and the inspector parses it, showing every message, field, type, default value, and documentation comment in a structured view. Avro schemas are parsed as JSON with full support for unions, arrays, maps, nested records, and logical types (date, timestamp-millis, decimal, uuid). Protobuf definitions are parsed with a hand-written proto3 parser that handles messages, enums, services, nested types, and rpc method signatures.
For Avro schemas, the tool can generate sample JSON data matching the schema — useful for building test payloads or documenting API contracts. For Protobuf, it lists every message with its fields, field numbers, and labels (repeated, optional). This is a read-only inspector, not a serializer: it helps you understand and document schema structures, not encode or decode binary data.
FAQ
What is an .avsc file?
An .avsc file is an Avro schema definition written in JSON. It describes the structure of Avro-serialized data: record names, field names, types (including nested records, unions, and logical types), defaults, and documentation. Avro is widely used in Apache Kafka, Hadoop, and data pipelines.
Can this parse proto2 syntax?
The parser primarily targets proto3, which is the current standard. Most proto2 features (required/optional labels, default values, extensions) are recognized but not all edge cases are handled. For complex proto2 files with extensions and custom options, use the official protoc compiler.
Does it validate the schema or just display it?
It validates structural correctness (valid JSON for Avro, valid syntax for Protobuf) and reports errors with context. It does not check semantic rules like field number uniqueness in Protobuf or compatible schema evolution in Avro — those require a schema registry.