Why Application Program Interface (API) is above Graphical User Interface (GUI)?

It’s been a long time since I have heard this tagline “API ABOVE GUI “ from many official testers within my friend circle and others .When I put some effort in realizing the fact behind this, I came across 2 reasons:

1)Agile practises
2)The Internet of Things .

Agile practises
With Agile development becoming the standard in most organizations, the ways in which we develop software and automate tests have changed dramatically. Graphical User Interface (GUI) tests that go against a user interface tend to take longer to run. During certain Agile practices like continuous builds, the amount of time it takes to receive feedback from a GUI regression suite of tests when new code is checked-in is too long. In those cases, quicker feedback is needed. Agile has also increased the frequency with which applications are released, which in turn has created an increased demand for new ways to quickly test them. GUI tests are typically too slow to get the test coverage we need during, say, a typical two-week sprint. Also, since Application Program Interface (API) tests don’t rely on a UI to be ready, they can be created early in the development process.

The Internet of Things
The second change that is causing a shift towards API testing is the Internet of things. The Internet of Things is an everyday object with embedded functionality that allows it to talk over the web using HTTP or HTTPS to communicate with remote backend services.

Basically, more and more things will begin to have sensors embedded into them. The other day I saw a video of Enchanted Objects: Design, Human Desire, and the Internet of Things author David Rose being interviewed by John Stewart, who showed a medication “glow” cap, that will tell you when to take your medicine by blinking or texting you so that you don’t forget. This is just one minor application, but I’m sure you can imagine the endless possibilities for this type of technology.
So most of the applications are without a definite traditional user interface .

So how do we test this?

This came with the result of API headless testing.


An API specifies how its software components should interact with each other. APIs can be created using a whole host of different technologies. APIs help facilitate communication between a client and a server. We are likely to be testing HTTP/HTTPS- based APIs where communication is done over the web. For example, say we have an internet scale that has an app that makes a request and receives a response from a backend service.


The benefits run over GUI platform as because of following:

Time effective:
If we are testing for a core functionality under a tight deadline we can often go for API.
For example, we executed 30,000 automated tests in a case study. It took 50 hours for GUI completion whereas took 8.5 hours in API.

Language Independent:
Data is exchanged through JSON or XML, so any core language can be used for automation .

Easy GUI integration:
Pursuing GUI after API, always give a perfect outline for the GUI stuffs.

Test Core Functionality:
Testing core functionality allows to access small errors, evaluate build strength, test in tandem with development, Improved test coverage and so on.

This in turn leads to faster release, conserved resources & advantageous in-house or off shore QA.

Latest stories

  • Go Live: 6 Things To Do Before Publishing an App

    After years of publishing applications to the app store, our team has come up with a checklist showcasing important things to do before publishing your app on Google Play or Apple App Store. Without further ado, let’s get started.  #1.Thoroughly Understand The App Store Policies and Guidelines It is vital to understand the app publishing […]

  • How to Create Mobile App Wireframe?

    Do you have an awesome app idea? Awesome!  No matter how amazing your idea for a mobile app is, if you are clueless about where to start and how to go about the development, it is bound to fail. So, after finalizing the app idea, the next step is wireframing. Why Wireframing? Incorporating all the […]

  • Designing The Ultimate Mobile App Architecture

    The strength of a building lies in its foundation. Similarly, architecture is the backbone of any mobile application. Building better app architecture is vital for the success of an app. Even the smallest fault in the architecture can undermine the quality of the app.  Factors to Consider While Developing Mobile App Architecture Before you dive […]

Leave a Reply

Your email address will not be published. Required fields are marked *