Agile development methodologies, microservices, and continuous integration have enabled an unprecedented level of experimentation, leading to exciting discoveries for developers and businesses. To keep pace with this ever-changing digital landscape, it is imperative for product teams to easily test applications’ functionality, possibly through automation. In the same vein, this article sheds light on the importance of API testing and how it is becoming increasingly crucial for product teams to test their product and detect anomalies quickly.
As a result, this article explains:
What is API Testing?
API (Application Programming Interface) testing involves testing the application programming interface against the expectations, use cases, and functionality needed. As a direct testing approach and a part of the integration testing paradigm, it proves to be integral for validating and understanding the functionality of the API and giving context to API’s quality, security, and usability.
Lately, with the advent of DevOps and the associated continuous delivery practices, API testing has become a breeding ground for test automation, and rightly so. Test cases, which are a part of the automated test suite, now help validate the functionality of an API quickly, regardless of its intricacy. Furthermore, the execution of these test cases, which might span multiple iterations, ensure that the API is working as expected and against the business requirements. Now let us have a closer look at the testing process.
Here’s what the process looks like:
- Define the scope of testing
- Decide the testing technique
- Prepare and plan the actual test cases
- Select an API testing tool
- Execute the test cases
- Identify errors (if yes, repeat from step 2)
- Handle, compare and report the results
- Maintain and optimize the tests based on learnings
Global Industry Analytics Inc., predicts the API testing market to reach $2 billion market value by the end of 2026. This growth is attributed to the higher dependency on aptness APIs and their ubiquity in the digital world.
Types of API Testing

It is essential to plan the test strategy before commencing the process. The testing strategy helps define the scope, purpose, and level of detail. With the help of a phased approach, it is possible to test it at every possible stage – from inception to evaluation. Certainly, the testing strategy best depends on the nature of the project. It also depends on the scenarios that are anticipated by certain levels of complexity.
Hence, after understanding API meaning, let us look at the types.
Below is the list of different types of API tests, each explicitly contributing to the overall development of the product.
Security Testing
Security testing focuses on how the API is utilized under stress together with penetration and fuzz testing. It involves checking for proper authentication, authorization, and other security-related parameters to ensure that authentication is efficient and secure. In addition, it further validates the encryption and access control of the API.
Load Testing
Load testing checks the robustness under high load and variability. The idea is to test the API under conditions where multiple, fast-paced requests are going through it simultaneously. Fundamentally, this ensures that the API can handle multiple requests at the same time. Meanwhile, complying with what the theory has laid out.
User Interface Testing
Although not entirely tied to the convention of testing the codebase, it serves a significant purpose that is vital to the application’s usability. As a part of the automated test suite or as a stand-alone testing approach, user interface testing ensures no issues with rendering and navigation.
Validation Testing
Towards the end of the development cycle, API testing starts with validation testing, w.r.t. the API’s function. The validation testing confirms that the API is functioning as expected and performs as per the specifications. The idea is to address a few questions like – Does the API respond timely and adequately? Is the API performing as planned under different conditions (load, response time, etc.)? Are there any issues with the API’s consistency between different endpoints and their responses?
Suggested Read- ACCELQ API Regression Automation
Benefits of API Testing

By now, it has been established that it is an integral part of the testing cycle. It helps to validate and qualitatively measure the success of business requirements through a defined test case process. More specifically, it helps with the following:
Top benefits:
Early Evaluation
Before the GUI testing, API testing helps evaluate the API early on and measure its success against a test suite. This prevents a lot of loss of time during the development cycle and over-engineering that might be necessary to address minor issues during the later stages.
CI/CD Compliance
Since it is possible to automate API, validating the business requirements through continuous integration and a continuous delivery pipeline is smooth. The end-to-end testing cycle is thus more efficient and relevant, as is the quality of the application.
Tight Security
Considering the combined prowess of fuzz, penetration, and security testing that API testing brings to the table, it becomes a robust and authoritative testing method against both the functional and the security anomalies that the API might face.
Time and Cost Reduction
The automation of API ensures that the time and resources invested are well-spent. Besides, the direct impact of API testing in quicker delivery, compliance to standards, better security, and a controlled scope is visible across every phase of development, making for a well-rounded testing strategy.
Platform Agnosticism
API testing ensures that the API can be deployed and tested across multiple technologies, regardless of the platform used. With the advantage of testing on different platforms and keeping the availability of both automated and manual testing continuous, testing an Application Programming Interface becomes a viable option for cross-development frameworks.
All these aspects serve as examples of the relevance of this type of testing. That is to say, it especially reduces the risk of delivering an application that is not yet market-ready.
Application Programming Interface testing has come a long way, and now it has stepped into the world of automation.
In this context, you might like to read: ACCELQ API Test Automation
Why ACCELQ for API Test Automation?
- Speed up the continuous delivery cycle by reducing the dependency on manual testing
- Facilitate end-to-end API validation through chain API tests
- Empower testing engineers to make more informed decisions on the run
- Maintain your standards and respond to business requirements rapidly
- Reduce the cost of development and maintenance of the codebase with a lean testing strategy
Do all that and more with ACCELQ’s codeless and automated API testing. We believe in striking a balance between speed and quality.