No. 8 of 24 ·Schema Registry Software

Karapace

Linux · Self-hosted · API · paid plans from $35/mo

Freedom report

Two barsScore 6.4

Free tierA free tier is on its own pricing page
Open codeNo open-source code on record
Runs widely1 of 6 device platforms
DocumentedPlans, terms and facts published

Karapace is ranked #8 of 24 in schema registry software on Freedom251. It runs on API, Linux, Self-hosted. There is a free plan. Paid plans start at $35/mo.

Karapace plans and pricing

All plans

Free Free $0/month Up to 250 KiB/s throughput · retention up to 3 days · up to 5 topics, each with two partitions · Schema Registry and REST proxy included aiven.io · 2 Oct 2026

Developer $35/mo $35/month; $0.04/hour Up to 1 MB/s throughput · retention up to 3 days · up to 20 topics (max 100 partitions) · Schema Registry and REST proxy included aiven.io · 2 Oct 2026

Compared on schema registry software

Schema formats: Avro, Protobuf, JSON Schema
Compatibility modes: NONE, BACKWARD, BACKWARD_TRANSITIVE, FORWARD, FORWARD_TRANSITIVE, FULL, FULL_TRANSITIVE
Validation scope: event
Deployment options: hybrid

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The record

What it does: Karapace is an Aiven-built open-source Schema Registry and REST Proxy for Aiven for Apache Kafka.
Schema management: The Schema Registry stores and versions schemas and can check compatibility before changes are published.
Supported formats: Karapace supports Avro, Protobuf, and JSON Schema registration; schema references are supported for Avro and Protobuf.
HTTP access: The REST Proxy exposes APIs for producing and consuming Kafka events over HTTP, including use from scripts, curl, and HTTP-based services.
Authentication: Karapace supports OAuth 2.0/OIDC authentication for Schema Registry and the REST Proxy.
Authorization: Schema Registry authorization uses access control lists, and OIDC role-based authorization can restrict operations by HTTP method.
Identity providers: The OAuth/OIDC setup documentation lists Auth0, Okta, Google Identity Platform, and Azure as example compliant providers.
Integrations: The Aiven Terraform Provider supports managing Karapace Schema Registry authorization ACL entries.
Deployment: The project documents Docker-based setup and installation from source with pip.
Compatibility: The project states that Karapace is compatible with Schema Registry 6.1.1 at the API level and supports all operations in that API.
Notable limit: Karapace’s built-in schema backup functionality was removed in version 6.0.0 and is no longer maintained in the project.
Free tier scope: Aiven’s Kafka free tier includes Karapace Schema Registry and is described as intended for learning, prototyping, and evaluation.
Company headquarters: Aiven says it is headquartered in Helsinki, Finland.
Founded: 2016
Price from: $35/mo

Where it ranks on Freedom251

Best Schema Registry Software in 2026#8 of 24

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Sources

aiven.io/docs/products/kafka/karapace· checked 2 Oct 2026
aiven.io/docs/products/kafka/karapace/howto/enab· checked 2 Oct 2026
aiven.io/docs/products/kafka/karapace/howto/enab· checked 2 Oct 2026
aiven.io/docs/products/kafka/karapace/howto/mana· checked 2 Oct 2026
github.com/Aiven-Open/karapace· checked 2 Oct 2026
aiven.io/docs/products/kafka/free-tier/kafka-fre· checked 2 Oct 2026
aiven.io/about· checked 2 Oct 2026
aiven.io/pricing/kafka· checked 2 Oct 2026