What is Automation Testing? Definition, How-to, and Best Practices

What is Automation Testing?

Automation testing is the practice of using scripts and specialized tools to automate test execution. It helps QA teams check issues in the system faster as compared to manual testing. 
 

Thanks to automation testing, testers don’t have to manually interact with the system over and over, which is a time-consuming process. All they have to do is click the “Run” button, sit back, and let the script do the work. Automated scripts and tools directly command the Application Under Test (AUT) to perform all actions on behalf of the tester.
 

Why is Automation Testing Important?

Software is literally carrying our modern world. They are so deeply entrenched in our life that a single bug is enough to cause rippling damage. I mean, who can possibly forget the unprecedented 8.5 million blue-screens-of-death around the globe in Jul 2024 that caused a loss of $10 billion? That's the power of a bug.

That’s when software testing, and more specifically automation testing, comes to the rescue. If software testing is simply checking bugs then automation testing is checking-bugs-on-steroid. It significantly speeds up testing while freeing up bandwidth for testers to focus on strategic tasks.
  

Is automation worth it? Yes, if the specific test case you are automating is highly repetitive. You’d be better off spending 1 hour scripting for a test that can then be automatically run hundreds of times than manually executing it hundreds of times all by yourself.

Here are the key benefits:

1. Improved accuracy: Automation testing cuts out human error by following exact, predefined steps every time. No missed steps or forgetfulness—just consistent execution.
2. Increased speed: Automated tests can be run 24/7, without breaks. That’s what machines are made for. What’s even better is that you can run them in parallel, which means running dozens or hundreds of tests at the same time, drastically cutting down testing time.
3. Cost savings: Though automation requires an upfront investment to create and maintain test scripts, the long-term gains in speed, accuracy, and consistency pay off nicely, especially for complex projects.
4. Enhanced test coverage: Automate tests once and reuse them across multiple browsers, devices, and operating systems. With cloud environments, you can even test on older versions effortlessly.
5. Improved test reusability: Once created, automated tests are ready to be reused—no need to recreate them for each cycle. Just hit the button and let them do their job.
6. Continuous testing: Automated tests can be seamlessly integrated into your development process, running automatically every time new changes are made. This ensures constant quality checks throughout the entire pipeline.

If you're a software business or an individual working in the digital industry, investing in automation testing will surely bring immense benefits to your product development process.

Learn More: Benefits of Automation Testing You Should Know

Which Test Cases To Automate?

Yes, automation testing is awesome, but not all tests can be automated. It’s all about “automation feasibility”.
 

A test case feasible for automation when it is:

1. Frequent: Tests that need to be run frequently and repeatedly.
2. Data-Heavy: Tests that require large datasets and many iterations.
3. Tedious: Tests that take too long or are just tedious when done manually.
4. Cross-Platform: Tests requiring execution on multiple hardware and software platforms.

How To Do Automation Testing?

Testing, in general, follows the Software Testing Life Cycle, which consists of 6 stages:

1. Requirement analysis
2. Test planning
3. Test case development
4. Environment setup
5. Test execution
6. Test cycle closure

No matter if you’re doing manual testing or automation testing, these steps are always followed in one way or another. What sets automation testing apart is at the Test case development stage.
 

For manual testing, you list down the test steps and then manually execute it step-by-step. For automation testing, you go the extra mile of writing the test script, but only have to click the “Run” button to execute.
 

Of course, there are so many more nuances in-between of this process, so let’s dive in to understand it in more detail!

Step 1. Choose your approach

To do automation testing, you have 2 approaches:

1. Use a test automation framework
2. Use a test automation tool

To best utilize a framework, you must have extensive coding knowledge yourself, and the effort to maintain test scripts is significant, but you can freely customize the framework to fit your specific testing needs.

A testing tool doesn’t require coding so you can easily create tests much faster. You can switch to coding mode whenever you want (if the tool offers coding mode). Test maintenance is usually taken care of, which reduces the workload. However, you are bound by the features offered by the tool, so it is recommended to list out the features you want from a tool to select the one that best fits your demands.

Step 2. Perform exploratory testing

If this is the first time you do automation testing for a certain system, you should first perform some exploratory testing to understand its features, so that you know what and where to test.
 

There is really no rule to exploratory testing. It all depends on your intuition, domain knowledge, and experience. Target high-risk areas such as complex features with intricate workflows, recently modified code, integration points, etc.
 

Ask yourself:

• What are the boundaries of this system? What happens when we push those boundaries? For example, what occurs if you input a username that is 10,000 characters long?
• What are the error messages? A system can work correctly in one way but fail in hundreds of ways. Focusing on these scenarios can uncover many unexpected bugs.
• What confusions have you encountered? If a certain area of the product seems confusing, is there something wrong with it?

Let’s Game It Out is a let’s play YouTube channel by a guy named Josh with chaotic evil energy. He embodies the exploratory testing spirit. Josh sets out to push every game he plays to its absolute limit and breaks the system. If you’re doing exploratory testing, do it like Josh.

Here's a fun video of how he breaks the game:
 

Once you have understood the system, you can start defining where to automate.

Step 3. Write the tests

Here comes the fun part.
 

Selenium and Cypress are two of the most popular automation testing frameworks out there. They support a wide variety of languages, so you can write in the one you feel the most comfortable with. Here’s a simple Selenium script written in Python to launch a browser, navigate to a website, click a button, and check if a certain result appear.
 

from selenium import webdriver

# Set up WebDriver (e.g., Chrome)
driver = webdriver.Chrome(executable_path='path_to_chromedriver')


# Navigate to a website
driver.get("https://testwebsite.com")


# Interact with elements (find a button and click it)
button = driver.find_element_by_id("myButton")
button.click()


# Check the result
assert "Expected Result" in driver.page_source


# Close the browser
driver.quit()
To familiarize with the commands, simply go through their documentation.

With automation testing tools, you usually get a host of features to support your test creation activity. For example, in Katalon Studio, you can leverage the Record-and-playback feature to record on-screen actions and turn them into an automation test script.

You can also use the Built-in keywords from the Keyword Library. These keywords are basically just pre-written code snippets to automate specific actions. String these keywords together and you should have a full test script ready to be executed across any environment.

For example, for the same test script above, you can piece these keywords together:

1. Open Browser (Chrome)
2. NavigateToURL (https://testwebsite.com)
3. Click (Element ID: myButton)
4. VerifyElement (driver.page_source)
5. CloseBrowser

Start Automation Testing With Katalon For Free 

Step 4. Prepare test environment

There will be clear hardware-software specifications for any testing projects, and that includes requirements on servers, databases, OS, browsers, and any third-party tools needed to perform the test.
 

For example, if you want to test a Login page, you need to prepare the browsers (Chrome, Safari, Edge), devices in a wide variety of versions (desktop, tablet, laptop, mobile), Operating system with suitable versions, and even suitable network conditions.
 

There are 3 types of environment you can go with:

1. Run tests locally with your device being the environment itself
2. Run tests remotely leveraging services like Selenium Grid or virtual machines
3. Run tests on-cloud leveraging platforms like AWS DeviceFarm

Step 5. Manage the tests

Test management is the glue that ties all testing activities together. It provides the much-needed structure and visibility to ensure a successful testing process.
 

It is about building a Testing Center of Excellence. This center is the central governing body that manages a shared pool of testing resources. For example, you can leverage Katalon TestOps to plan tests, schedule test runs, organize test suites, manage test data/artifacts/objects, and centralize test reporting.

Thanks to this unification, stakeholders from QA teams, devs, and PMs can gain a shared visibility on the testing process, which improves overall efficiency.
 

Step 6. Execute tests & analyze results

With all that ready, you can start test execution and gather results.

Read more: Steps To Build A Good Automation Test Report
 

Challenges of Automation Testing

Of course, automation testing is not without its challenges. There is usually some compromise to be made when you want to increase testing speed. What’s important is whether that compromise is worth it or not. 

According to the State of Quality Report 2024, the most prevalent challenge to automation testing is the team's lack of skills and experience in test automation, with up to 45% of respondents agreeing, followed by 38% thinking that requirements change too often, and another 26% claiming that test maintenance is costly. 

→ Download the State of Quality Report 2024 to get the latest industry insights
 

Automation Testing Best Practices

1. Start with Test Case Prioritization: begin with the ones that are high-priority, repetitive, and stable. These are your regression tests and smoke tests. They’re like the foundation of your automation suite because they’re run often, cover critical functionality, and are less likely to change dramatically. By automating these first, you’re tackling the biggest wins upfront—saving time, reducing risk, and getting quick feedback on key areas of your application.
2. Use Data-Driven Testing:  if you’ve hardcoded your test data into the script, you’re in for a long, tedious rework, but if you use data-driven testing, you separate the test data from the test logic, making your tests way more flexible and reusable. Think of it like changing outfits—you’re keeping the same core (the person), but you’re just swapping out the clothes (the data). Suddenly, you can run the same test across multiple scenarios with ease.
3. Maintain modular and reusable scripts: nobody wants to reinvent the wheel every time they need a new test. That’s where the beauty of modular, reusable scripts comes in. Let’s say you’ve written a script that logs into your application. Why not break that out into its own module? Then, every time you need to test something that requires a login, you can just plug in that module instead of rewriting it. This not only saves you time but also keeps your scripts lean and easier to maintain. Plus, when the login flow changes (because we all know that’s inevitable), you only need to update it in one place.
4. Regularly review and update tests:  automation testing isn’t a “set it and forget it” kind of deal. Software evolves—features change, UI gets revamped, and workflows shift. If your tests don’t evolve with it, they’ll become outdated, unreliable, and worse—misleading. That’s why it’s essential to regularly review and update your tests. A little maintenance now and then keeps everything running smoothly and prevents small issues from turning into big problems later on.
5. Integrate with CI/CD pipelines: automation testing opens up the possibility of CI/CD integration. With this, you’re turning the whole testing process into a well-oiled machine. Every time a developer pushes new code, your tests automatically run, providing instant feedback. Fast feedback means faster fixes, which means happier users and smoother releases.
    

Wrapping Up

In conclusion, automation testing is a critical component of any software development process. With the right tools and approach, organizations can improve the speed and accuracy of their testing, catch bugs earlier in the development cycle, and ultimately deliver better products to their customers.
 

If you don't know which test cases to start with, here’s a list of popular test cases for you. They should give you a good foundation of how to approach a system as a tester. 

1. Test Cases For API Testing
2. Test Cases For Login Page
3. Test Cases For Registration Page
4. Test Cases For Banking Application
5. Test Cases For E-commerce website
6. Test Cases For Search Functionality