Avro Schema Viewer
List fields and their types from an Avro .avsc file.
Overview
The Avro schema viewer pretty-prints a .avsc file as a flat list of fields with their types, default values, and documentation. Paste a schema you've pulled from Kafka Schema Registry or a Confluent topic and immediately see the record shape without scrolling through nested JSON.
Data engineers and platform teams reach for an avro schema viewer when investigating a producer/consumer mismatch, drafting downstream SQL, or comparing schema versions in code review. It saves the eye-strain of reading verbose Avro JSON by hand.
How it works
Avro schemas are JSON documents that describe records, enums, arrays, maps, and unions. The viewer parses the root schema, walks every nested type, and flattens it into rows keyed by dotted JSON pointer paths. Union types like ["null","string"] are shown as string? to signal nullability the way most language bindings do.
References to named types defined earlier in the schema are resolved so each row shows the concrete leaf type. Logical types (decimal, timestamp-millis, uuid) are surfaced alongside the underlying primitive.
Examples
Input:
{
"type": "record",
"name": "User",
"fields": [
{"name":"id","type":"long"},
{"name":"email","type":["null","string"],"default":null}
]
}
Output:
User.id long
User.email string?
Input: {"type":"record","name":"Event","fields":[{"name":"at","type":{"type":"long","logicalType":"timestamp-millis"}}]}
Output: Event.at long (timestamp-millis)
FAQ
Does it support schema references and $ref?
Avro uses named-type lookup rather than JSON Schema $ref. Named types defined in the same schema are resolved automatically; cross-file references aren't supported because they require a registry context.
Can I paste a schema bundle from Confluent Schema Registry?
If you have the raw .avsc JSON, yes. Strip the registry envelope ({"subject":...,"schema":"..."}) first and pass the inner schema string, decoded.
What about Avro IDL (.avdl)?
Only the JSON schema format is supported here. Compile your IDL with avro-tools idl2schemata first to get the .avsc files.