UI Automation Vs. API Automation: Top 3 key differences

UI Automation Vs. API Automation, what’s the difference, who cares and should I be concerned about this for my site?

UI Automation Vs. API Automation

Honestly, this is only going to matter to your programmer, but if you want to learn about UI automation and API automation this is a quick read.

What are UI Automation and API automation?


UI Automation gives assistive technology products like screen readers programmatic access to most user interface (UI) elements on the desktop, allowing them to communicate information about the UI to end-users and alter it via methods other than standard input.

Automated test scripts can also interact with the UI using UI Automation.


Application Programming Interface is the abbreviation for Application Programming Interface.

Typically, an API is used to make it easier for two different apps to interact through any means of communication.

APIs have recently become the backbone of programming. As part of integration testing, API automation can help speed up the process and boost efficiency.


UI Automation Vs API Automation

1. Development takes a long time:

A user interface test imitates the end user. As a result, these scripts do all of the chores a human would handle on the front end. This usually entails loading screens/pages, writing / reading a large number of fields/elements, and a lot of waiting. Even with a highly reusable framework, scripting all of these tasks takes time.

The end outcome of the entire exercise is usually a series of data transfers between the client and the server. This is the development phase; keeping UI testing up to date is considerably more difficult. Because the code base is several times larger than API level tests, it is also quite expensive to maintain. Maintenance costs rise when the code becomes more sophisticated and has more lines of code.

2. Fragility:

Anyone who has worked in automation for more than a few months has experienced the vulnerability of UI test scripts. The resilience of these scripts can be raised to a tolerable level by following good development practices, although UI tests are fragile by nature. The UI elements can change quickly, browser version updates can cause behavior changes, response times fluctuate between browsers, and the list goes on.

UI automation was, for the most part, the only sort of automation that most people utilized back in the day. As a result, there was no standard against which UI testing could be compared. The comparison was between efficient frameworks/tools versus inefficient frameworks/tools, and now it ranks at the bottom. 

3. Test coverage has been reduced:

It’s difficult to reproduce a lot of business logic from the front end.

Some product features require very particular and thorough environmental parameters to trigger that line of code on the business layer. For this, UI automation is ineffective.

It would be impractical in many circumstances, especially when other hardware is involved, such as a car refueling hardware device sending data to a web server after the refuel is complete. You may simply simulate the message on the API/Integration layer instead.

Compared to API level or unit level tests, even small operations on the UI take a long time, which has the unintended consequence of covering a lot less ground.




Implementing a unified framework for UI and API testing is a great way to get a complete understanding of your project from start to finish and solve quality concerns at its source.

There are additional benefits:

  • API TEST can be used to double-check front-end UI logic.
  • With UI setup and API execution, optimize permutation and combination.
  • API permutations and combinations for cross-functional testing
  • Tracing a defect is now easy



Ultimately, it’s not necessary to create lots of UI test scenarios where each field is validated for various incorrect entries, because a) you already created those scenarios in your API tests. 
In fact, converting your UI tests to API tests will make your regression suites faster and more reliable. If you already have a bunch of UI tests in place, it may be a good idea to take a look at your tests and see if any of these scenarios could be covered by API testing.