Manual vs. automated testing – how to choose the right approach

In the world of software development, there is no one-size-fits-all testing path. Each project has its own characteristics, and the choice between manual and automated testing should be based on those specifics. In this article, we explore the differences between these two approaches, their pros and cons, and when it’s best to choose one over the other—or combine them wisely.

Software testing is a critical part of the application lifecycle. It helps detect bugs and ensures quality. There are two primary testing approaches: manual testing and automated testing. Each has its advantages, limitations, and suitable use cases across different types of projects.

What Is Manual Testing?

Manual testing involves a tester manually checking the application’s functionality. The tester performs test cases, observes the results, and compares them with the expected behavior.

Advantages of manual testing

Among the advantages of manual testing are:

• flexibility: easy adaptation to new scenarios and quick responses to changes in the project.
• low short-term cost: no need to create and maintain test scripts.
• better usability insights: testers can catch UX/UI issues that are difficult to identify through automation.
• easier implementation: no specialized technical knowledge required.

Disadvantages of manual testing

Despite its many advantages, manual tests also have disadvantages. Among them we can mention:

• time-consuming: each test must be performed individually, making the process slower.
• lack of scalability: manually testing every feature becomes difficult in large-scale projects.
• prone to human error: routine and monotony may lead to overlooked bugs.

When to Use Manual Testing?

Manual testing is a good fit for:

• projects with frequently changing interfaces: when the application is under heavy development and the UI changes often, automation becomes costly and hard to maintain. Manual testing allows for faster adaptation.
• exploratory and UX/UI testing: human judgment is irreplaceable in identifying unusual bugs and evaluating usability, intuitiveness, and design.
• projects with limited budget or time: when resources are constrained, manual testing allows for a quick start without investment in test infrastructure or automation scripts.
• one-time or irregular tests: when test scenarios are not frequently repeated, manual testing is more cost-effective and flexible than automation.

What Is Automated Testing?

Automated testing uses tools and scripts to perform tests without human involvement. Testers write scripts that can be executed repeatedly.

Advantages of automated testing:

• speed and efficiency: scripts can run many tests in a short time, especially useful for regression testing.
• repeatability: automation eliminates the risk of human error present in manual testing.
• scalability: ideal for large projects with numerous test scenarios.
• cost-effective long-term: once written, scripts can be reused multiple times.

Disadvantages of automated testing:

• high initial costs: creating test scripts requires time, resources, and technical expertise.
• maintenance: scripts need regular updates, especially in fast-changing applications.
• lack of adaptability: scripts don’t detect UX/UI flaws or unexpected behaviors.

When to Use Automated Testing?

Automated testing is particularly valuable for:

• regression testing: with frequent updates and code changes, automated tests help verify that new features haven’t broken existing ones. You can learn more about regression testing and other test types in our article.
• long-term projects: the cost of automation is offset over the project’s duration.
• large-scale systems: automation is effective when the volume of test cases exceeds what can be handled manually.
• projects requiring high repeatability: critical systems like banking or healthcare apps, where precision and stability are essential.

Manual vs. automated tests – key advantages and disadvantages

Preparing Applications for Automated Testing

To enable effective automation, the application must be prepared accordingly:

• stable user interface: automated tests are sensitive to UI changes. Unique identifiers for interface elements are essential.
• defined key test paths: identify which functionalities require automation and focus on the most critical ones.
• choosing the right tools: automation tools (e.g., Selenium, Cypress) should match the project’s nature.
• test data management: ensure the availability and consistency of test data.

Should You Automate All Tests?

Despite its many advantages, test automation is not always the best solution. Automation makes sense for:

• repeatable tests (e.g., regression).
• time-consuming, tedious manual tests.
• precision-critical tests.

However, exploratory, UX/UI, and human judgment–based tests are better handled manually.

„Manual and automated testing complement each other. Automation is a long-term investment that offers significant benefits, particularly in regression testing and large-scale projects. Yet manual testing remains indispensable in areas that require human intuition and evaluation. The key to success is selecting the testing approach that fits the project’s specifics and combining both methods in a balanced way,”

– says Zbigniew Michniowski vel Michniewski, Senior Quality Specialist at 3Soft.