Manual Testing vs Automation Testing: A Full Comparison

Manual testing vs automation testing: a comparison

QA professionals have 2 approaches when it comes to software testing: manual testing vs automation testing. Each has its own advantages and disadvantages that testers must consider to optimize test resources. In this article, we dive deep into these 2 approaches, provide best practices, highlight their differences, and show you when you should choose one over the other.


First, let's understand the 2 concepts before diving into the comparison.

What is Manual Testing?

Manual testing is a type of software testing where a human tester executes test cases manually to identify defects in the software application. In manual testing, the tester performs various actions on the software application, such as entering data, clicking buttons, and navigating through the menus, to ensure that the software functions as intended and meets the specified requirements.


Read More: What is Manual Testing: A Complete Guide


What is Automation Testing?

Automation testing is a type of software testing that involves using specialized tools and software to execute predefined test cases automatically without human intervention. It involves the creation of automated test scripts, which simulate the actions of a human tester by interacting with the software application's user interface or APIs. The test scripts are designed to test the software's functionality, performance, and reliability, and they can be executed repeatedly to identify defects and ensure the software's quality and stability.

Read More: What is Automation Testing? Ultimate Guide & Best Practices


Manual Testing vs Automation Testing: Which is Better?

The short answer for this question: it depends.

Admittedly, automation testing brings such a wide array of benefits that no organization can ignore. Automating thousands of repetitive test cases significantly reduces the workload for human testers, speeds up testing, shortens the testing cycle, reduces time-to-market, and improves testing efficiency overall. 


Automation testing is particularly effective for large-scale regression testing where thousands of test cases have to be executed time and time again. In this respect, human testers prone to make human errors can’t match the level of consistency and accuracy of a machine.

However, for smaller projects, ad-hoc testing, and exploratory testing, manual testing shines through. The effort to create automation test scripts for these cases is much higher than just manually testing them, for 2 reasons:

  1. Such test cases are not repetitive, and automating a one-off task is counterintuitive
  2. The goal of these tests is to discover the unknown, hidden bugs and not based on predefined test cases. It requires human creativity, which is something machines don’t have

Moreover, in smaller projects there may be not enough information on whether a test case is repetitive enough to be automated. The effort to maintain automated tests at the early stage is higher than executing them manually. Therefore, the final decision heavily depends on business requirements, time, resource constraints, and objectives of the software development project. 

For your convenience, we have prepare a brief comparison between those 2 testing approaches:


Manual Testing

Automation Testing


Testing software manually by humans without any automation tool or script

Testing software using automation tools or scripts written by humans

Human Intervention

Requires significant human intervention and manual effort

Requires less human intervention 





More prone to human error

More reliable as it eliminates human error


Test cases cannot be easily reused

Test cases can be easily reused


Can be expensive due to human resources required

Can be expensive upfront due to automation tools setup but cheaper in the long run


Limited scope due to time and effort limitations

Wider scope as more tests can be executed in a shorter time


Unable to handle complex tests that require multiple iterations

Able to handle complex tests that require multiple iterations


Depends on the skills and experience of the tester

More accurate as it eliminates human error and follows predetermined rules


Easy to maintain since it does not involve complex scripts

Requires ongoing maintenance and updates to scripts and tools


Requires skilled and experienced testers

Requires skilled automation engineers or developers


How To Do Manual Testing?

No matter what type of testing they chose, testers all have to follow the Software Testing Life Cycle (STLC). The STLC consists of 6 major activities to ensure that all software quality goals are met.

Software Testing Life Cycle for manual testing vs automation testing

Requirement analysis gives the QA team a general understanding of the testing objectives. This will be the foundation for them to create a test plan, which include detailed instructions on how to perform the test and what the expected test results are.

Once the test environment is ready, testers manually execute the test cases, record the results. Details on the bugs are communicated to the development team, who will start troubleshooting the issues. After defects have been fixed, the QA once again manually retest the affected functionality to confirm that the bug has truly been resolved.

That is a lot of work for testers considering the effort it takes to manually enter test data and interact with app elements to find bugs. For quality management at scale, manual testing is counterproductive. Having to manually login and logout every time a code change happens to test if that feature is still working is soul-crushing, but we can’t afford to ignore it, since a broken Login feature means negative impact on the bottom line. Learn more about Software Testing here.

Let’s use the example of an eCommerce website to further illustrate the amount of work it takes to do manual testing. There are a wide variety of features, functionalities, and information to be tested on an eCommerce web, including:

  1. User registration: Enter the required information such as name, email address, password, and phone number. Click register. Check that the user receives a confirmation email and is able to log in to the website using the registered credentials.
  2. Product search: Test the search functionality of the website by searching for a specific product using different search terms. Check that the search results are accurate and relevant to the search terms.
  3. Product details: Verify that all the relevant information about the product is displayed, such as the product name, price, description, images, and reviews.
  4. Add to cart: Add a product to the cart and verify that the cart displays the correct product information, including the quantity and total price.
  5. Checkout process: Enter valid shipping and billing information and complete the purchase process. Verify that the order is placed successfully and the user receives a confirmation email.
  6. Payment methods: Select different payment options, such as credit card or PayPal, and verify that the payment is processed successfully.
  7. Account management: Test if the user can edit their profile information, view their order history, and manage their saved payment methods.
  8. Accessibility: Test if the website's features and functions are accessible to users with disabilities, such as screen readers or keyboard-only users.

eCommerce websites are usually huge. There must be a separate product page for each product and a category page listing products of similar attributes. This pushes the number of pages to be tested to the thousands, if not millions for established brands. A quick Google search with the “site:” parameter for the domain - a leading eCommerce fashion brand returns 8,510,000 results, which means this domain has more than 8.5 million pages to be tested! Finding bugs for those pages is already a challenge, but having to manually retest them to confirm that the bugs have been resolved is what makes manual testing truly exhausting.

manual testing vs automation testing in terms of effort and resources required


Read More: 100 Test Cases For E-commerce Websites

When To Use Manual Testing?

Manual testing is only ideal when the scenario is complex and non-repetitive, making investing in automation for them time-consuming. Another scenario is when testers want to evaluate the application from the end user’s perspective, providing a more genuine and human feedback to the development team.


Ebook From manual to automation 5 esential steps.png

How To Do Automation Testing?

Automation testing is essentially executing test scripts containing sets of instructions to simulate user actions and interact with the software application in a specific sequence. We first need a test framework, which gives testers the tool(s) they need to create, execute, debug, and manage test scripts.

Organizations have 2 options: either they shop around for a vendor offering a software with the test frameworks they need, or they build the test framework themselves using open-source automation libraries. Building the software in-house offers great customization and ensures high compatibility with the existing techstack, but it is extremely resource-intensive and time-consuming, while buying a testing tool allows teams to get started quickly thanks to many pre-built features.

Having the necessary tools and frameworks, testers can start automation testing following the Software Testing Life Cycle. It all starts with identifying test cases to automate, especially repetitive, critical, and time-consuming ones. 

After that comes Test Case Development. Selenium is a common library used to create test scripts. Below is an example of an automation test script to test the login function of a website using Selenium written in Java.

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
public class LoginTest {
    public static void main(String[] args) {
        // Set the path to the Chrome driver executable
        System.setProperty("", "path/to/chromedriver.exe");
        // Create an instance of the ChromeDriver
        WebDriver driver = new ChromeDriver();
        // Navigate to the website
        // Find the login link and click on it
        WebElement loginLink = driver.findElement(By.linkText("Login"));;
        // Find the username field and enter the username
        WebElement usernameField = driver.findElement("username"));
        // Find the password field and enter the password
        WebElement passwordField = driver.findElement("password"));
        // Find the login button and click on it
        WebElement loginButton = driver.findElement("login-button"));;
        // Check if the login was successful
        WebElement welcomeMessage = driver.findElement("welcome-message"));
        if (welcomeMessage.getText().equals("Welcome, myusername!")) {
            System.out.println("Login test passed.");
        } else {
            System.out.println("Login test failed.");
        // Close the browser


In this script, we first set the path to the Chrome driver executable, create an instance of the ChromeDriver, and navigate to the website. We then find the login link and click on it, enter the username and password, and click on the login button. Finally, we check if the login was successful by verifying the welcome message displayed after login, and print the result to the console.

This is only a simple example. The downside of this approach is that as soon as an element changes, all of its dependencies must also be changed accordingly, or else the test script breaks or becomes unreliable. 

With an automation testing tool, testers have to code very little, if at all. Katalon - as an all-in-one automation testing tool - offers a Record-and-Playback feature in which testers can put in the URL, choose the browser, and record actions that have to be performed many times.

Katalon automation testing tool Record and Playback feature


All actions you perform on the page, including scrolling, clicking, data entry, etc. on page objects are recorded and saved as a test case. This feature truly simplifies and speeds up the test creation process.



Interested? Learn More About Katalon Here


CURA Healthcare automation testing

Many automation testing tools also provide libraries that contain a set of built-in keywords for different actions and validations. These libraries can be accessed by testers in their test scripts and used to perform various tasks. Built-in keywords are typically designed to be flexible and customizable, so that they can be used in a variety of scenarios. Testers can provide parameters to the keywords, which specify the details of the action or validation being performed. For example, a "click" keyword might take a parameter that specifies the ID or name of the element to be clicked.


test better with automation testing tools

When To Use Automation Testing?

Automation testing shines when manual testing is no longer useful. Most notable is regression testing and retesting, where the same test cases are repeatedly executed after each change or update to the software. Another use case is for cross browser/cross environment testing, where testers have to run tests across multiple browsers, devices, and operating systems. The chart below shows the number of iPhone screen sizes. Releasing a new app on the App Store means conducting mobile testing on all of those screen sizes - that is a lot of work if we don’t have automation testing.


Display Size

Display Type

Dimensions (mm)

iPhone 14 Pro Max



160.7 x 77.6 x 7.85

iPhone 14 Pro



147.46 x 71.45 x 7.85

iPhone 14 Plus



160.8 x 78.1 x 7.8

iPhone 14



146.7 x 71.5 x 7.8

iPhone SE 3



67.3 x 138.4 x 7.3

iPhone 13 Pro Max



160.8 x 78.1 x 7.4

iPhone 13 Pro



146.7 x 71.5 x 7.4

iPhone 13



146.7 x 71.5 x 7.4

iPhone 13 Mini



131.5 x 64.2 x 7.4

iPhone 12 Pro Max



160.8 x 78.1 x 7.4

iPhone 12 Pro



146.7 x 71.5 x 7.4

iPhone 12



146.7 x 71.5 x 7.4

Automated regression testing is also faster, more efficient, and more consistent because there is less room for human error, which is why it is well-suited for large-scale testing. Let’s take the example of the eCommerce website above. Instead of manually testing the functionality of User Registration, Product Search, Product Detail Display, Add To Cart function, Checkout process, Payment Method, Account Management, Accessibility, and many more, testers can simply automate all of them. No matter how many web pages there are to be tested, all can be done within the click of a button.


Read More: A Complete Guide To Cross-browser Testing


How To Switch From Manual Testing To Automation Testing?

After weighing on the benefits of automation testing and the potential ROI you can achieve, it’s time to start switching from manual testing to automation testing. Let's see how you can do automation testing in just a few steps using Katalon.

Katalon logo

Katalon is a comprehensive automation testing solution that allows QA teams of any maturity levels to start automation testing at ease. To start, download and install Katalon


Download Katalon and Witness its Power in Action

Once you have downloaded Katalon, it's time to create your first test case:

create a mobile test case in Katalon

In Katalon, you can test anything. It supports web testing, mobile testing, API testing, and also desktop testing. Within Katalon Studio, you have a productive IDE with 3 test creation modes:

- No-code mode: turn on the Record-and-Playback mode, then perform all of the testing actions as you would during manual testing sessions. Katalon recognizes your sequence of on-screen actions and turn it into a fully executable automation test script that you can reuse across enviroments.

- Low-code mode: in this mode, you can gain access to a huge keyword library to automate any action you want. These keywords are essentially code snippets. Piecing keywords together is to piece code snippets into a full script. 

built-in keywords in Katalon Studio for keyword-driven testing

- Full-code mode: want full customization? Turn on the Scripting mode and start coding. Switch back to the Low-code mode whenever you want. Enjoy the simplicity of Record-and-Playback coupled with the flexibility of Scripting mode.

After all of that, navigate to the Run icon and choose your desired environment:

execute test cases in Katalon Studio


You have successfully done automation testing without really having to code. It's just a few clicks away!


Learn More About The Katalon Platform


Download Katalon and Witness its Power in Action

Automation Testing Best Practices

1. Select the right test cases for automation

Not all test cases are suitable for automation. Focus on test cases that are repetitive, time-consuming, or require large amounts of data. This ensures that you get the most value out of your automation efforts. Automating every test case is actually impractical, which may lead to false positives and/or negatives.

2. Choose a good automation testing tool

To ensure successful test automation and efficient use of testing budget, it is important to select the right automation testing tool that supports the application being tested and the testing requirements. Consider the following criteria when selecting an automation testing tool:

  • Compatibility: The tool should be compatible with your software development environment, including your operating system, programming language, and any other tools you are using.
  • Functionality: The tool should have the necessary functionalities to create, run, report, and debug tests. Most tools support a few specific testing types, so if you need a comprehensive testing tool, consider a quality management platform.
  • Usability: The automated testing tool should have a user-friendly interface that is easy to navigate, with clear instructions to help you perform your tests effectively.
  • Scalability: A good testing tool should be scalable to meet the demands of your testing needs, both now and in the future, as your software evolves and grows.
  • Integration: A good automation testing tool should be able to integrate with other tools you are using, such as your bug tracking system or continuous integration platform, to help streamline your testing process.
  • Support: The tool should have good customer support and a vibrant community, with resources such as forums, online tutorials, and knowledge bases.
  • Security: The tool should have adequate security measures in place to protect your data and ensure that your tests are performed securely.
  • Reputation: The tool should have a good reputation in the testing community, with positive reviews and recommendations from other users and experts.

Read more: Top 15 Automation Testing Tools | Latest Update in 2024

3. Implement proper bug documentation and test reporting

Ensure that you have a workflow in place to capture and report bugs, and that the bug reports are detailed enough to help developers identify the root cause of the issue. A good test report should include details like the test case, the expected outcome, the actual outcome, and any screenshots or logs that can help reproduce the issue. This will help stakeholders get a clear understanding of the test results and enable them to take appropriate action.

Can automation replace manual testing?

Automation testing has many benefits, such as speed, efficiency, and repeatability, yet it cannot replace manual testing entirely, at least for now. Exploratory testing, usability testing, and ad-hoc testing are manual testing, and they always require human intuition, experience, and creativity to uncover issues that might not have been detected by automated tests.

Nevertheless, organizations should always strive to move from manual testing to automation testing to leverage all of the benefits it brings.


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