Karate vs REST Assured

Free tier available

Free and open source

Open source core; Karate Labs sells a commercial IDE and enterprise support separately.

Free and open source. You pay in engineering time and CI minutes.

The open-source framework is complete and free.

Everything, self-hosted

Widely used

Karate Labs · since 2017

Widely used

OSS community · since 2010

• One DSL covers functional API tests, mocks and load tests — rare consolidation.
• Powerful JSON matching that removes most assertion boilerplate.
• Non-Java testers can write meaningful tests.

• API tests live in the codebase, versioned and reviewed with the service.
• Readable given/when/then chains that map directly onto HTTP semantics.
• Full access to Java for setup, data and assertions.

• The custom DSL is another language to learn and cannot be refactored by an IDE.
• Debugging complex scenarios is harder than in plain code.
• The UI automation feature is far behind dedicated browser tools.

• Java only, and requires developers rather than manual testers.
• No GUI, so exploratory request work needs a separate client.
• Verbose for very large payload assertions.

Teams wanting API testing and mocking in one tool, including non-Java testers.

JVM teams that want API tests in the same repository as the service.