Schemathesis vs REST Assured

Free tier available

Free and open source

Open source. A commercial hosted service exists for reporting and continuous runs.

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

The CLI and Python library are open source and free.

Everything, self-hosted

Established

Schemathesis · since 2019

Widely used

OSS community · since 2010

• Enormous coverage for almost no authoring effort — the schema is the test suite.
• Reliably finds unhandled server errors and schema violations that manual tests miss.
• Failures come with a minimal reproducing case.

• 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.

• Only as good as your schema; a vague or inaccurate spec produces noise.
• Tests conformance, not business correctness — it cannot know a discount was miscalculated.
• Generated failures can be tedious to triage at first.

• 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.

Any team with an accurate OpenAPI spec who wants deep coverage cheaply.

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