Karapace vs Redpanda

Karapace is Aiven’s open-source Schema Registry and REST Proxy for Aiven for Apache Kafka. The registry stores and versions schemas, then checks compatibility before a changed schema is published. It accepts Avro, Protobuf, and JSON Schema, with references supported for Avro and Protobuf. Compatibility modes include NONE, BACKWARD, BACKWARD_TRANSITIVE, FORWARD, FORWARD_TRANSITIVE, FULL, and FULL_TRANSITIVE. The REST Proxy exposes HTTP endpoints for producing and consuming Kafka events, so scripts, curl, and HTTP services can work with events. OAuth 2.0/OIDC authentication is available for both components. Registry ACLs and OIDC role-based rules can limit operations, including by HTTP method. Example identity providers include Auth0, Okta, Google Identity Platform, and Azure. Deployment documentation covers Docker and installation from source with pip; the API is stated to support Schema Registry 6.1.1 operations. Karapace is available in Aiven’s Kafka free tier for learning, prototyping, and evaluation. The Free plan costs nothing, while Developer costs $35 a month.

Redpanda is an event-streaming platform for storing real-time events in ordered topics that can be replayed, with access through the Apache Kafka API. Its Kafka compatibility is intended to let existing applications and tools continue without rewrites or changes. The platform uses a native C++ architecture, runs as a single binary, and has no external dependencies. Redpanda Connect supplies more than 300 pre-built connectors for sources, sinks, processors, databases, APIs, cloud services, and AI pipelines. Native Apache Iceberg support and Iceberg topics let streams be materialized into lakehouse-ready tables. Deployment options include Serverless, managed BYOC on AWS, GCP, or Azure, and self-managed installations on bare metal, virtual machines, Kubernetes, or Docker. Redpanda also lists stream processing, a schema registry, both delivery guarantees, and client support for Java, C/C++, Go, Python, Rust, and Node.js. The maker states that its platform delivers 10x lower tail latencies than open-source Kafka.