Test yourself under real exam conditions: 50 timed questions, 60 on the clock, pass mark 70%%. Instant score with a full review of everything you got wrong. Free — no account needed.
Exam details
API testing verifies that an application's interfaces behave correctly in terms of functionality, contracts, performance, security, and error handling.
It catches issues below the UI layer, runs faster than end-to-end tests, and provides direct confidence in service behavior.
Unit tests isolate small pieces of logic, integration tests verify components working together, and API tests validate behavior at the service boundary.
A contract describes the expected structure and behavior of requests and responses, including fields, types, and status codes.
Status codes communicate success, failure, and semantics to clients, so incorrect codes can break integrations even when payloads look reasonable.