Why API Testing ?

In previous post, I talked about some of the misconceptions between API and Webservices and some of the webservices types (SOAP and REST).

In this post, I will be talking about the importance of API Testing along with some pros and cons of it. So, let’s start with it.


  1. Faster Execution/Feedback
  2. Testing can be started early in SDLC since API is developed before GUI
  3. Less cost to fix the bug found by API Testing (since it is found early in STLC)
  4. Easier (but trickier) to create than GUI Tests
  5. Test Reuse (if multiple applications uses the same API)


  1. Hard to visualize API Test as it is not visible as compared to GUI Test
  2. Developers Support needed in order to proceed with API Test (in case of lack of proper documentation)
  3. Difficult to debug the failing API Tests (as nothing is visible)
  4. Specialized knowledge about HTTP Verbs, Request Structure etc is needed
  5. Added layer of Security Testing / API Monitoring when functionality is implemented as API instead of GUI


Difference between GUI and API Testing can be understood from the below image:

api test flow

Moreover, Google Trends data shows huge inclination towards API Testing in recent years:

google trends



One thought on “Why API Testing ?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s