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We're here to help you find itMaster API testing with Koenig to validate REST, gRPC, and GraphQL services. Gain hands-on expertise to secure endpoints and achieve professional AT*SQA certification success.
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Explore API testing certification and training courses — delivered live by certified instructors.
API testing is a type of software testing that evaluates application programming interfaces (APIs) directly to verify functionality, reliability, performance, and security. It operates at the message layer, sending requests and analyzing responses without a graphical user interface. As a core component of integration and microservices testing, it ensures systems communicate correctly and deliver expected results under varied conditions. Key tools and frameworks used in API testing include Postman for designing and executing manual and automated API requests, REST Assured for Java-based test automation of RESTful services, and SOAP UI for functional, regression, and load testing of both SOAP and REST APIs. These tools support validation of JSON and XML responses, authentication protocols like OAuth 2.0, data-driven testing, and integration into CI/CD pipelines using Jenkins and Maven. API testing is designed for QA engineers, test automation specialists, and developers working with microservices or distributed systems who need to validate backend logic, ensure service reliability, and accelerate testing cycles without relying on UI layers.
HTTP Fundamentals
Explain HTTP methods, status codes, and header usage
REST Principles
Design and test RESTful endpoints using resource conventions
API Authentication
Implement token-based and cookie-based authentication flows
JSON Handling
Parse and validate JSON request and response payloads
Testing Tools
Use Postman, REST Assured, or Playwright for API calls
OpenAPI Specs
Read and interpret OpenAPI/Swagger documentation for endpoints
The building blocks every API testing solution is made of
See what your official API testing certification looks like. Download a sample — then let our advisors map the fastest path to earning the real one.
ISTQB-CTFLISTQB Certified Tester Foundation Level
POSTMAN-STUDENTPostman API Fundamentals Student Expert
SMARTBEAR-READYAPISmartBear ReadyAPI Certification
ISTQB-CTAL-TAISTQB Certified Tester Advanced Level - Test Automation
POSTMAN-API-NETWORKPostman API Network Badge
SMARTBEAR-SWAGGERSmartBear SwaggerHub Certification
Official credential badges — shareable on LinkedIn
Four formats. One quality standard. Every option comes with the same expert instructors, official courseware, and money-back guarantee.
Every factor that determines whether you actually pass your API testing exam — rated across every training format available.
| Criteria | Koenig | Free Platform | Self-Paced Platform | ALP Provider | Legacy Provider | Note |
|---|---|---|---|---|---|---|
| Trainer quality and credentials | ||||||
| MCT-Certified Trainers | — | |||||
| Live instructor-led delivery | — | |||||
| 1-on-1 private training | Partial | — | ||||
| ISTQB Partner Status | ||||||
| Official ISTQB ALP Status | — | |||||
| ISTQB Official Courseware | Partial | — | ||||
| ESI / EA Credits Accepted | — | |||||
| Flexibility and access | ||||||
| Any-day / Flexi start | — | |||||
| On-site / Fly-Me-A-Trainer | Partial | — | ||||
| Global delivery reach | Partial | — | ||||
| Results and trust | ||||||
| Exam pass rate | — | |||||
| Entry price | ~$745 · best value | Free | Free | ~$1,500+ | $15-30/mo | — |
| Verified learner reviews | 18,400+ · 4.9★ | N/A | N/A | Limited | N/A | Row omitted on live page: unverified for this vendor |
Data sourced from public pricing pages and review platforms. Accurate as of March 2026. Partial = available in select regions only.
Verified reviews from learners certified on Azure, AI, Security, and more.
From our headquarters in India to training centers across UAE, Iraq, Saudi Arabia, UK, USA, Singapore, Australia, and more — Koenig delivers Microsoft certification training in 50+ countries.
