Automation Testing vs. Manual Testing: Rivals or Strategic Partners?

No matter how innovative or well-designed a solution is, if it’s not rigorously tested, it will likely fail when it hits the real world. 

Bugs, missed requirements, or unforeseen issues can derail the most promising projects.

And then you’re faced with a challenge: 

How do you organize your QA? Manual or automated testing? When do you need to choose, and when could choosing one over the other hurt you? 

To complicate things further, let’s throw AI into the mix.

We promise – it’ll all make sense when you finish this article.

Too many words, too little time? 

Why Is It So Expensive to Ignore Quality Software Testing?

Software testing is one of the fastest-growing tech industries, with the market for it valued at $40 billion in 2021 and an anticipated Compound Annual Growth Rate of 6% between 2022 and 2030. The importance of quality assurance in the software industry is not up for debate, which is proven time and time again by seemingly promising solutions that eventually fail due to the lack of testing.

The difference between automated testing and manual testing is a decision every team has to make at some point. But how do you know which one is right for your project?

• How to plan a balanced testing process?
• When should you choose automation, and when is manual testing the smarter option?
• Can automation really replace manual testing, or do you need both?
• What role does AI play in all of this?
  

Let’s break it all down.

What is manual testing?

Manual testing is a process based on the QA engineer executes tests by hand without using automation tools. It’s a human-centered approach, offering a perspective no machine can fully replicate.

This type of software testing has existed since the early days of software development, long before automation tools existed. Initially, it was all about basic functionality checks — making sure the software worked as expected. QA engineers would manually run through each feature, clicking every button and checking for glitches.

Today, manual testing has evolved but remains a vital part of the quality assurance process. Now, it covers complex areas like usability, exploratory testing, real-world user behavior, tasks that automation still struggles with. 

No matter the benefits of automation testing, without manual QA efforts, many popular software products wouldn’t be as polished, secure, or enjoyable for users.

Key Uses of Manual Testing

Manual testing is the first type of QA a company usually considers maintaining or improving the quality of the application. And in many cases, it remains the only type of testing used on a project. Here are a few situations when manual testing is suitable:

1. In the initial development phase. Functionality and application state constantly change at this stage, and the manual approach is better equipped to adapt quickly. Automation requires significant resources to set up and maintain, which isn’t always feasible for early development.
2. For short-term or small projects. Manual QA doesn’t require the lengthy setup of automation tools, making it ideal for smaller projects that immediately need to establish software testing process. It can be introduced in days rather than weeks, allowing for more immediate feedback and adjustments compared to test automation frameworks.
3. When testing usability. Automation tools also mimic some user interactions, but they still lack human intuition. Manual testing shines when it comes to understanding the subtleties of user experience.
4. During user acceptance, ad-hoc, or exploratory testing. These types of testing require to engage with the product in unpredictable ways, something automated testing cannot replicate. Manual QA specialists use their judgment to test scenarios that haven’t been predefined, which can reveal unexpected bugs or user issues.
5. For testing physical products. Whether it’s IoT devices, automotive software, or medical technology, testing the interaction between hardware and software often requires hands-on manual testing.
   

When prioritizing flexibility and real-time adjustments. Manual testing is done for real-time adjustments and flexibility during the process. Testers can quickly adapt to unexpected changes or new insights, something that’s harder to achieve with automation, which requires reconfiguring scripts and tools.

When Not to Use Manual Testing

Manual QA has limits, especially when automation provides more efficiency and accuracy. Here are key instances where it may fall short:

• When you have repetitive tests. Running the same tests repeatedly is time-consuming and prone to errors. Automation can handle these tasks more efficiently.

• When you need to eliminate human error. Human error is always a factor, no matter how skilled your team is. Automation provides more consistent results for tasks where accuracy is critical.

• For long-term or large-scale projects. When a project requires continuous and large-scale testing, manual testing becomes impractical. The difference between manual and automation testing is the most stricking when it comes to scaling.

• When working with large datasets. Manual testing struggles with the sheer volume of data processing tasks. Automation can process vast amounts of information faster and more accurately.

• When speed is essential. Setting up automation takes time, but once in place, it runs much faster than manual testing, making it the better choice when time-to-market is critical.

Obviously, if you can’t, or better say, wouldn’t prefer to use manual testing, you still need to use something. And it is the time we move towards automation.

What is Automation Testing? 

Automation testing involves using tools and scripts to run tests automatically, reducing the need for manual input. It’s especially useful for repetitive tasks and large-scale projects where speed and accuracy are crucial.

Automation test scripts emerged as software grew more complex and projects demanded faster release cycles. Initially, it focused on automating simple, repetitive tasks, but it has evolved to handle more advanced testing like regression, load, and performance testing.

With the ability to run hundreds or thousands of tests simultaneously, automation can quickly identify issues in a fraction of the time manual testing would take.

Today, automation testing uses frameworks that are essential for tasks that require precision, speed, and scale — things that are difficult to achieve manually. It ensures that software remains stable during updates, handles heavy traffic efficiently, and can process large volumes of data without errors.

Key Uses of Automation Testing

While the advantages of manual QA are vast, we wouldn’t be having the discussion over automation testing vs. manual testing if it wasn’t for the immense benefits of using automation QA where it’s appropriate. 

For example, automation can ultimately reduce the cost of testing by 85%. What is time-consuming in manual testing, automated testing allows to speed up significantly.

But how do you actually choose manual vs automation testing? Here is when to automate testing to achieve even more efficiency of testing and increase the quality of the product:

1. For repetitive tasks. When the same tests need to be run repeatedly, automation handles these tasks quickly and consistently, freeing up testers to focus on more complex testing challenges.
   
2. For large-scale projects. Automation allows you to run hundreds or thousands of test cases simultaneously, covering a vast range of scenarios that would take much longer to execute manually.
   
3. When testing for performance and load. Automation is crucial for simulating heavy traffic and stress-testing systems. It helps identify how well your software performs under pressure, something that’s difficult to replicate manually.
   
4. When you perform regression testing. After every code change or update, automation can quickly check that new changes haven’t broken existing functionality. This makes regression testing much faster and more reliable than manual checks.
   
5. For handling large datasets. When dealing with vast amounts of data, automation processes it far faster and more accurately than a person ever could.
   
6. To minimize human error. Automation eliminates the risk of skipping steps or making mistakes, especially in high-stakes testing where accuracy is critical.
   
7. For integration testing. When multiple systems or components need to work together, automation ensures all the moving parts are tested efficiently and consistently.
   
8. To accelerate time to market. Automation reduces the time spent on repetitive testing tasks, allowing you to release software faster without sacrificing quality.
   
9. When creating reusable test scripts. Once an automated test script is created, it can be reused over and over, increasing efficiency and saving time in the long run.
   

To support continuous integration (CI). In CI environments, automation is essential to ensure that new code changes are tested as soon as they are merged, keeping the development cycle smooth and fast.

When Not to Use Automation Testing Tools

Despite what some may say, and even though some companies now exclusively have automation testers in their QA departments, auto QA cannot replace manual testing.

Here is when building an automation system and automated tools be useless or even harmful:

1. For exploratory or ad hoc testing. These testing types require creativity and adaptability, where human intuition and flexibility are key. Automation is faster than the manual, but it can’t replicate the out-of-the-box thinking needed here.

2. When the project is short-term. Setting up automation takes time, and the investment may not be justifiable for short-term or smaller projects. Manual testing can provide faster feedback in these cases.

3. When usability testing is critical. Automation tools can’t fully replicate the human experience. Manual testing provides better insights for tasks like evaluating a product’s user interface or overall usability.

4. When tests need to run only once or twice. If a test doesn’t need to be repeated regularly, automation may not be worth the time and resources required for setup.

5. When the system or product is still in rapid development. In fast-changing environments, automation can become outdated quickly. Manual QA is better suited to handle constant updates without reconfiguring test scripts.

6. When the cost of automation is too high. Setting up automation frameworks, maintaining them, and hiring specialists can be costly. In some cases, manual testing is testing that is a much more practical and budget-friendly option.
   

Manual Testing vs. Automation Testing: Cost, People, Time to Market, and Beyond

There are different ways to compare and distinguish between manual and automation testing. We can look at what these two methods can achieve and their tools. However, some of the most important aspects of the automation vs. manual testing debate can be found more practically. There are human and material resources behind every QA project, whether it’s manual or automated. Time to market is also an essential metric that needs to be accounted for. Here is a breakdown of those key parameters.

Cost

According to some estimates, software testing can account for as much as 60% of the overall cost of a software project. There is no secret that testing automation costs more money than manual testing at the beginning of the project, when it takes high-paid automation QA and sophisticated tools to set up the automation process.

However, thanks to test reusability and other factors, automation testing also helps save money in the long run. Automation tests are appropriate for long-term and large-scale projects, whereas manual testing is best suited for smaller, short-term testing challenges.

So what costs less: manual testing or automated testing? It all depends on the size and the planned future of your project. Cutting costs on testing is possible — hire hiche experts who know how to test only what’s necessary, don’t pursure automation system and check test build just for the sake of it, and spend some time on development and QA strategy. 

Human resources

A skilled and experienced dedicated testing team of manual testers can make a lot of difference in the quality of a software product. Still, although manual testing can significantly impact software quality, there is no denying that any manual QA operation requires significant human resources. As every test case will be created, run, documented, and reviewed by hand, manual QA specialists will always have their plates full, no matter how big the team is.

Automation testing, on the other hand, helps optimize the use of human resources. Sure, automation QA may be more expensive to hire. Still, when a single automation QA engineer is doing the work of several manual QA, it’s a good investment to hire one. This is the difference between automation and manual testing, which requires a large team to keep the project going.

Accessibility for newcomers

As long as the software industry exists, there is going to be a need for software testers. This rapidly growing and changing industry never fails to attract newcomers. And we can confidently say that manual testing is still the more attractive field for newcomers for one simple reason: the entry threshold for manual QA is significantly lower than that for automated QA. Manual QA engineers don’t need deep knowledge of coding or automation frameworks to join the industry and perform testing at an acceptable level.

At the same time, it doesn’t mean that a manual QA will stay in the same position forever. The software testing industry allows to venture into related fields with relative ease. Plenty of manual QA experts eventually switch to a new field known as automation testing. However, that shouldn’t be viewed as a vertical career move or an example of QA evolution. Rather, it’s a lateral move, as both manual and automation testing engineers have the same end goal — they just use different skills and tools to achieve it.

As for the situation when a developer switches to QA automation, this career move has its benefits, such as deep knowledge of code needed to effectively automate large volumes of test cases. However, this situation is not without its challenges, as many former developers have a very particular approach to writing test cases for automation.

Both manual testing and automated testing are attractive fields for newcomers, and although they require different mindsets and sets of skills, both of them can be excellent career paths.

Time to market

In a time where the competition in the software market is stiffer than ever, and there already seems to be a software product for everything, fast time to market can be the one critical advantage the company needs to succeed. This is why this parameter also matters for the manual testing vs. automated testing discussion.

With its reasonable resource use and ability to launch fast, manual testing is a good fit for an application in the active development stage. However, manual testing doesn’t always positively impact the product’s time to market because it takes a large group of testers and a long time to cover every aspect of a software product.

Automation testing is able to generate test results significantly faster than manual testing and can locate more bugs in the same amount of time than manual QA. And given that the same automation test case suite can be run daily and bring relevant results, it can definitely decrease the time to market. At the same time, it’s important to remember the Pesticide Principle paradox — if the test case suite is not regularly reviewed and updated, it can lead to the product only performing well within the limits of the suite. This is why the real people can bring a human perspective to the process, and help avoid the test suite becoming outdated.

Manual Testing vs Automated Testing: The Ultimate Showdown

The automation testing vs. manual testing debate wouldn’t be complete without a detailed look at each type’s benefits and limitations. Here is a comparison of manual and automation testing using the most important criteria in QA.

How AI Supports Automation and Manual Testing

Artificial intelligence steps in to make the processes faster and more focused. It flags what you might miss and points you to the areas needing attention. 

There are several excellent test automation tools in the market that make life better for all — startups, enterprises and us, outsourcing companies. 

AI in Manual Testing

At first glance, manual QA seems like an unlikely place for AI to make an impact. After all, manual testing is driven by human insight and creativity. But AI is a useful assistant, helping testers focus on the most important areas.

• Smarter test case generation. AI can analyze historical test data and application behavior to suggest test cases. This helps testers cover more ground, particularly in areas they might have overlooked. For example, AI can flag edge cases that are easy to miss during manual test planning.

• Test prioritization. AI can help prioritize the most critical areas for testing based on past bugs or real-time data, ensuring manual team members spend their time when it’s most needed.

AI doesn’t replace the human element in manual testing—it enhances it by guiding testers toward smarter decisions and giving them more time for creative, exploratory testing.

AI in Automation Testing

AI has a natural synergy with automation. It accelerates the automation process, makes it more efficient, adaptable, and less prone to repetitive mistakes:

• Self-healing test scripts. One of AI’s most useful applications in automation is maintaining test scripts. As applications change, minor UI adjustments can break automated tests. AI can detect these changes and automatically update the scripts, saving time and reducing maintenance costs.
  
• Intelligent test prioritization. Instead of running an entire test suite every time code changes, AI can suggest the most critical tests to run based on what parts of the code were affected. This reduces testing time and helps catch high-priority issues faster, especially in larger projects.
  
• Enhanced visual testing. AI can analyze visual elements of the application across different devices and screen sizes, identifying inconsistencies or bugs that traditional tests might miss. This is particularly helpful for cross-device testing, where subtle visual bugs can slip unnoticed.
  

Performance testing insights. AI tools can sift through performance data to flag potential bottlenecks and suggest optimizations. In one case, AI helped detect an unexpected increase in database queries affecting user flow performance.

No More Automated Testing vs Manual Testing: Holistic Strategy Is On

Whether you’re dealing with a fast-changing small project or a massive system with lots of moving parts and significant scaling perspective, we have a check-list for you. It will help you decide when to rely on human insight and when to let automation take over. 

Project size and complexity

• Is the project small with frequent changes? → Go with manual for flexibility.
• Does it involve a large, complex system? → Lean on automation for scalability.
  

Repetitiveness of tasks

• Are tasks being repeated often? → Automate to save time.
• Are tasks unpredictable or one-off? → Manual testing is your best bet.
  

Usability and human interaction

• Does success rely heavily on user experience? → Use manual testing for better insight into usability.
• Is it more about performance under load or repeated tasks? → Automation can handle that.
  

Time constraints

• Need faster feedback loops? → Automate where possible.
• Need deep, exploratory testing? → Stick with manual testing.
  

Budget and resources

• Do you have the budget and expertise for automation? → Invest in automation to handle repetitive tasks.
• Tight budget or limited team experience? → Stick to manual or consider outsourcing automation expertise.
  

Rarely does a project rely solely on one method. In most cases, it’s a balance—manual testing for creativity, automation for speed, and AI to enhance both. Often, you need to integrate all three approaches, outsourcing the expertise you lack.

Manual Testing Or Automated Testing Based on a Product Development Stage

Stage 1: Establishing the Foundation 

Manual testing is hands-on, creative, and flexible — perfect for those early stages when the software is still taking shape. No automation can replace human intuition when it comes to spotting unexpected issues.

Use manual testing for:

• Exploratory testing, where intuition and creativity are essential.
• Usability testing, where understanding user behavior makes all the difference.
• Early development stages when things are constantly changing.

Human insight is crucial. But manual testing also sets the stage for future automation by identifying areas for regression testing.

• Start with manual testing to check the critical areas.
• Document test cases during manual testing that can later be automated.
• Keep flexibility a priority — be ready to adapt as the project evolves.

If you’re working on a small project with little iterations, manual testing might be all you need for now. 

Make sure you do it right, though. 

When it’s time to scale, you’ll rely on the groundwork you’ve laid with manual testing to transition smoothly into automation. Skipping this step can lead to issues that automation alone can’t fix.

Stage 2: Scaling with test automation

Once the foundation is in place with manual testing, automation steps in to handle repetitive, large-scale tasks that would be time-consuming for manual testers. Automation is all about speed, consistency, and handling massive amounts of data or scenarios efficiently.

Use automation testing for:

• Regression testing. Ensures that code changes don’t break existing functionality by re-running tests across different builds quickly and reliably.
• Performance and load testing. Simulates heavy usage scenarios, helping to identify bottlenecks or stability issues in large-scale applications.
• Repetitive tasks. For test cases that need to be executed frequently or across multiple configurations, automation provides consistent results faster than manual efforts.

Automation excels when you need speed and scale. But it’s important to remember that automated scripts aren’t “set and forget.” They require regular maintenance to stay relevant as your software evolves.

• Identify high-value test cases for automation. Focus on repeatable, high-impact tests, such as regression suites or performance tests that are time-consuming for manual testers.
• Use AI to boost automation. Use AI tools to automatically generate test cases, adapt scripts when minor UI changes occur (self-healing scripts), and identify which test cases to prioritize based on recent code changes.
• Integrate automation into CI/CD pipelines. Ensure that automated tests run with every build, providing immediate feedback on code quality and minimizing delays in release cycles.

Stage 3: Adding AI for optimization

AI in Manual Testing

• Helps testers prioritize areas that need attention by analyzing past bugs or usage data.
• Assists in generating test cases, especially for edge cases that might be overlooked.

AI in automation testing

• AI-powered tools can automate test creation, making maintaining and expanding test coverage easier.
• Self-healing scripts: When minor UI changes break automated tests, AI can automatically fix the scripts, reducing the need for manual updates.
• Optimizes test execution, focusing on the most critical areas to avoid running unnecessary tests.

AI enhances both manual and automated testing by providing data-driven insights. It helps teams work faster and more accurately, but it doesn’t replace human intuition or judgment.

• Use AI tools to assist in creating smarter test cases.
• Regularly review AI-assisted test performance and fine-tune the results as needed.
• Use AI to keep your testing efforts lean, running only the most valuable tests while maintaining high quality.

Here is one of the cases we’ve dealt with recently, where AI played critical role. 

The overnight test suite rescue

Our e-commerce client pushed a non-planned critical bug fix with under-the-hood UI changes at 5 PM on a Friday. Our entire test suite of 500+ tests was suddenly broken. Monday’s launch was non-negotiable.

The AI solution. We relied heavily on our AI tool’s self-healing capabilities. By Saturday morning, it had updated and fixed… 80% of the broken tests.

The outcome. We manually fixed the remaining 20% by Sunday afternoon. The release went ahead on Monday as planned.

While not perfect, AI significantly reduced our workload, making a seemingly impossible deadline achievable.

If you want to see more AI-related practical cases, check our newsletter, we’ve covered a few success stories there: “AI in QA Automation: The Rookie’s Annual Review.”

Brief Check-up: Is Your Testing Strategy Holistic?

• Have I identified areas where human insight is critical?

Some tasks need a human touch, like exploratory or usability testing. Have you clearly defined those areas?

• Am I automating repetitive and time-consuming tasks?

Automation should handle repetitive tests to save time. Are you still manually testing where automation would be faster?

• Are my manual and automation efforts aligned?

Both methods should work together. Are your manual testers helping guide future automation, and is automation freeing them up for more critical tasks?

• Am I using AI to assist with testing?

AI can enhance both manual and automated testing. Are you using it for tasks like generating test cases or prioritizing tests?

• Do I review and update automation scripts regularly?

Automation scripts can become outdated quickly. Do you check and refresh them as the software changes?

• Have I considered scalability?

Does your strategy account for future growth and scaling, taking into consideration the difference between manual and automation testing? 

• Is my testing providing fast and useful feedback?

Are your tests integrated into your CI/CD pipeline, ensuring fast, actionable feedback with each new build?

10 Key Takeaways: Balance the difference between automation testing, manual and AI approaches

#1. A holistic approach is the future. It’s no longer about choosing between manual and automation testing—both are essential for a balanced QA strategy.

#2. Manual testing lays the groundwork. Human insight is key, especially for exploratory and usability testing, where intuition and creativity are required. It also helps identify areas for future automation.

#3. Automation increases speed and consistency. Automated tests handle repetitive tasks, regression testing, and large-scale scenarios faster than manual efforts.

#4. AI enhances both approaches. AI tools support manual QA by prioritizing test cases and suggesting overlooked edge cases. For automation, AI enables self-healing scripts, smarter test case generation, and better execution efficiency.

#5. Identify high-value tasks for automation. Focus automation efforts on repetitive, high-impact tasks like regression or performance testing, allowing manual testers to work on complex, critical areas.

#6. Don’t neglect maintenance. Automated test scripts require regular updates and adjustments as the software evolves, ensuring they remain accurate and relevant.

#7. AI-driven test prioritization is key. AI helps optimize test execution by focusing on critical areas, avoiding unnecessary tests and ensuring faster, more targeted feedback.

#8. Scalability matters. Automation helps handle large-scale projects and data-heavy scenarios, but scaling should also consider the ongoing need for human insight in specific areas.

#9. Review and update regularly. Manual and automated tests and AI-assisted tools need continuous review and optimization to stay effective as the software grows.

#10. A well-rounded strategy is the goal. Combining manual testing’s flexibility and automation’s efficiency, enhanced by AI, creates a testing strategy that adapts to your project’s needs while improving quality and speed.

Wrapping Up: Will Automation Replace Manual Testing?

The debate between manual and automation testing has been ongoing for years, but it’s no longer about choosing one. Both methods have their strengths, and together, they create a more complete and effective QA strategy.

• Manual testing brings creativity, intuition, and the ability to handle unpredictable scenarios.
• Automation testing delivers speed, consistency, and the power to scale testing efforts.
• AI acts as the bridge, optimizing both manual and automation processes with data-driven insights.

In this article, we explored:

• The best use cases for manual testing and why it still matters.
• How automation testing saves time and improves accuracy in repetitive tasks.
• The role of AI is enhancing both approaches, helping testers work smarter, not harder.

The future of QA lies in combining these elements. 

Manual testing will always be needed for its flexibility and human touch, but automation and AI will continue to push the boundaries of what’s possible, improving efficiency and coverage.

Rather than asking if automation will replace manual testing, it’s time to focus on building a holistic strategy that uses the strengths of all three. 

The end goal is better software that is delivered faster and has fewer bugs slipping through the cracks.