Web app testing – tools, methods, strategy and more

Web applications are part of our everyday lives. We use them for work, education, entertainment and much more. It is important that web applications are of high quality, secure and reliable.

We must all agree that in today’s constantly changing and competitive world, the internet has become an integral part of our lives. Most of us now make decisions based on information searches on the internet, so website hosting is no longer optional but mandatory for all types of businesses. It is the first step to becoming and staying relevant in the market.

But just having a website is not enough. The organisation must create a website that is informative, accessible and user-friendly. To retain all these features, the website should be tested well and this process of testing a website is known as web application testing.

What is web application testing?

Website testing is the process of verifying that web applications and websites work as they should. Web testers use a variety of methods to test web applications, including manual testing, automated testing, and load testing.

By verifying that web applications work properly, web application testers can help ensure that users have a positive experience when using them. In addition, web application testing can help identify and fix web application bugs before they cause problems for users.

Why is web testing necessary?

  • Website testing is essential and necessary after feature development, because without proper website testing we cannot ensure bug-free delivery of the software to the customer.
  • Website testing allows you to detect and report product defects. If testers do not perform thorough testing, there is a high probability that end users will report problems. If customers are dissatisfied with the end product, they will be hesitant to delegate any new function to the team.
  • If testers don’t perform thorough tests of web applications, the risk of bugs and the likelihood of losing customers is high. Compromises in software quality have a negative impact on a company’s reputation.
  • Website testing is critical to delivering high-quality software. Only by performing website testing can developers ensure that a product does not have critical bugs.
  • Providing bug-free software to the market attracts new customers, which ultimately drives an increasein revenue.

Benefits of web application testing

  1. Increased performance

One of the main benefits of web application testing is increased performance, which is largely provided through performance testing. Performance tests are designed to assess how the system behaves under a specific load, how quickly it responds and how much load it can handle.

This is very important for web applications because poor performance can lead to high churn rates, loss of users and ultimately a drop in revenue. A web application that has undergone thorough performance testing will load quickly, handle high traffic volumes without problems, and function smoothly even under load. This not only increases user satisfaction but also helps in achieving better search engine rankings, which can have a positive impact on your business.

  1. Reduction of maintenance costs

Test automation is a key benefit of web application testing that plays a significant role in reducing maintenance costs. Automated tests are software scripts that automatically test your application. They are faster, can be scheduled to run at any time and reduce the risk of human error.

In the long run, automated testing dramatically reduces the time spent on repetitive testing, allowing your team to focus on more complex tasks. In addition, because automated tests are repeatable, they help identify problems early in the development cycle, avoiding costly fixes later in the cycle.

  1. Increased user satisfaction

When testing web applications, it’s all about the end user. The main goal is to ensure that the app is easy to use, works well and provides the necessary functionality. It involves testing the app from the user’s perspective, ensuring that it is intuitive, user-friendly and meets the user’s expectations.

Testing helps identify and fix any bugs or issues that may determine the user experience. A well-tested app results in happy users, increased user retention and higher conversion rates.

  1. Improved security

With the increasing number of cyber threats, security has become a major concern for all web applications. Safety testing and security testing are key components of web application testing. These processes help identify any vulnerabilities or weaknesses in the application that could be exploited by hackers.

A secure web app not only protects your business data, it also builds user trust. Users can interact with your app without worry, knowing their data is safe. In a world where data leaks are becoming all too common, a secure web application can be a significant competitive advantage.

The challenges of web application testing

Interaction with firewalls

Connection problems with firewalls arise because a port or firewall can block a web application because of problems with security certificate compliance. Therefore, it is very important to test the application over multiple firewalls to avoid such scenarios.

Web services authentication

Modern web applications rely heavily on web service layers such as XML/SOAP or JSON/REST to exchange data between applications or systems. Therefore, the need for authentication of these web services has increased significantly. However, web service testing platforms are not equipped to handle them. As a result, testing web services poses a significant challenge for QA teams.

Consistency across browsers

Customers always prefer scalable and highly interactive web applications. If customers encounter inconsistencies when browsing across different browsers, it can have a negative impact on the image and brand growth of a business. Therefore, developers and QA testers need to monitor the scalability and interactivity of the application across different browsers and hardware configurations when testing usability.

Solving performance problems

Users abandon every slow-loading web app, which ultimately affects a company’s brand and revenue. Thus, to overcome this obstacle, developers should identify factors affecting performance testing, such as scalability of application features, compatibility, and integration constraints.

Securing the web app against data leaks

The number of cyber threats that can leak sensitive user data is constantly increasing. It is essential to monitor security testing processes to prevent information loss and data leaks. This will help prevent DDoS attacks and other cyber threats. If any problems are found, testers can fix them as soon as possible.

Web application testing vs. desktop application testing

  • Website testing is URL-based testing and runs in many web browsers. On the other hand, testing of desktop applications is done by testers on a single computer or system.
  • Testing desktop applications requires an understanding of the user’s interaction with the application. In addition, testing web applications also requires knowledge of the operating system and database.
  • Testing desktop applications involves evaluating elements such as the graphical user interface (GUI), load, and backend. During testing of desktop applications, memory leaks and exceptions must be evaluated. Web applications can be accessed simultaneously by multiple users over the Internet. Web applications running on two or more systems are complex, requiring extensive testing.
  • To test a web application, the tester must be familiar with the functionality of the application to interact with the end user. Website testing verifies testing of static application pages, browser compatibility and overall functionality of features.
  • Cross-browser testing is essential for automated testing of web applications, while it is not applicable for testing desktop applications.
  • Web application testing does not require installation/uninstallation testing, while the same is required for desktop applications.
  • Security/authentication testing is critical when performing website testing because multiple users access the application. On the other hand, authentication testing does not need to be done extensively for a desktop application because it is usually accessed by a single user.
  • Testers perform stress testing to evaluate a website by having multiple users access the application at the same time. On the contrary, desktop applications are used by a single user, so application behavior is not analyzed when only one user accesses them.
Web application testing is an important part of the development process
Testing web applications is an important part of the development process.

Web application testing techniques

  1. Testing functionality and features

Functional testing is practically the most basic but extremely important testing for any application, including web applications. Functionality testing ensures that the web application works correctly. Best web application testing tools check factors such as whether every link on a website points to the right page.

Functional testing includes:

  • Unit testing: this phase of functional testing tests small areas of the application in the early stages of development to reduce the likelihood that more serious bugs will occur later.
  • Smoke testing, build verification testing, and trust testing: after each application build, this test is performed to verify that the web application is stable and ready for further testing to avoid wasted testing effort
  • Sanity Testing: after the build verification is complete, this test checks the new code and specific features introduced
  • Regression testing: repeated testing of a select list of test cases to identify areas that respond more rigorously to change and to ensure that existing functionality remains functional
  • Integration testing: components of the software are gradually integrated and then tested as a unified group. Usually, these components are already working well individually, but they may break when integrated with other components.(e.g. redirection to the mail page after successful registration for email verification).
  • Usability Testing – is used to find areas to improve the overall UX design based on the behaviour and feedback of the actual user.

Functional testing also tests forms to make sure they work.

  1. Testing Web APIs

Web APIs, as the name suggests, are application programming interfaces for the web. API testing requires making requests to multiple API endpoints to verify the response. This can measure many things including function, security and performance. API testing is essential because it tests the logic, responses, security, and bottlenecks (weaknesses) of the application’s performance.

For example, let’s say you want to test a login form. You want every username and password you enter to be stored correctly in the database.

In terms of APIs, you are examining the transfer of data between endpoints. If you want to encrypt and protect HTTP data exchanges from potential hackers, work with negative test cases such as:

  • Access to the API without following the authentication rule.
  • Testing for invalid values in JSONS (e.g. cannot register a user with a non-existent email address).

Cookie testing is another aspect to focus on when sending user-specific requests and sessions. With the API as an intermediary, parameters are often added to API functional test cases to delete or store information from user sessions and activities.

  1. Database testing

Database testing ensures that the data values and information stored in the database are valid. It will help prevent data loss, salvage lost transaction data and prevent unauthorized access to information.

Testing includes checking the schema, tables and triggers of common databases such as Excel/CSV, GraphQL, Oracle SQL and SQL Server. It often involves stress testing and using complex queries on one or a combination of data sets. Database testing is a confidence provider in ensuring the successful transfer of all data regardless of the pressure exerted.

  1. Testing regressions

Working with large software or applications means constantly releasing changes. Basically, unless the software is created for personal use, new features and code modifications are something to be expected by default. Code changes can reveal unexpected dependencies and failures.

Regression testing ensures that the application continues to work after code changes, updates, or other enhancements. This is a crucial step as it is responsible for the overall stability and functionality of the existing features of the application.

Fortunately, regression testing is often an ideal candidate for automation. Test cases that cover the primary areas of the software; the login page and the home page; are set up to be selected and run whenever needed.

  1. Cross-compatibility testing with browsers, operating systems and mobile devices

Cross-compatibility testing ensures that the core functionality of your web app is available to users across different browsers, devices and assistive tools. This includes not only different operating systems, but also different versions of systems.

Not all operating systems, browsers and devices are built the same. This is what can cause inconsistencies in the behavior of web applications in different test environments, and why it is important to test for cross-compatibility.

These things, from API connectivity to navigation between pages, can easily change based on where your app’s users are coming from. Older versions of browsers, operating systems and mobile devices haven’t disappeared for a reason – users are still using them. One such example of how applications can be affected by cross-compatibility is the phasing out of Internet Explorer and switching to Microsoft Edge.

Of course, testing and enabling compatibility across all existing browsers, platforms and devices is not realistic. If you want to know which ones to focus on, it’s best to work with the relevant departments (e.g. marketing or product). They have insights that we might not, and they can help you make a list of priorities.

In addition, be sure not to skip responsiveness testing. Ensuring consistency across a range of screen sizes in layout, spacing, vertical/horizontal scrolling, alignment and scaling of elements is equally important.

  1. User interface (UI) and visual elements testing

Visual aspects are often overlooked. Most teams consider functionality to be the critical area, not how aesthetically pleasing the user interface looks. It usually only hits when the organization starts to scale. If you reset the CSS or override the default layout with your own design, you may experience layout design issues. The causes may be different, but the most practical solution is testing.

Not every browser, operating system or mobile device reads data in the same way. New browsers with cutting-edge technology are often up-to-date with the most advanced CSS and JavaScript options. Whereas in older ones, such as Internet Explorer, 3D graphics can only be displayed as a flat design.

This test requires a thorough check by the UI and UX developers to make sure that everything is still displaying as it should and that all images are in the right places in the right proportions.

  1. Web security testing

Site security is one of the most important steps in web testing. In particular, thorough web testing ensures that your web application is built to withstand any hacking attempts or data breaches.

Potential data breaches can lead to the leakage of users’ personal information, including stolen personal data, passwords and login credentials, or banking and financial information. Leaking any personal data can result in extremely costly legal problems for you and your business.

That’s why security testing is an essential process to use when testing your web application. Security testing for the web allows you to:

  • Search for potential gaps and threats
  • Comply with the laws that govern the security and privacy policies of the site
  • Perform a top-down review of the application to understand the current security capabilities of the application
  • Respond quickly to breaches or hacker attacks in the future
  1. Performance and loading speed testing

Finally, we test the performance and loading speed. We’ve already made sure that everything else works with the web app, but now we need to see if the app takes longer than 2 seconds to start.

JavaScript files, third-party plugins, multiple page sizes or components that take longer to load can reduce the speed of your website. Testing the load speed will give you guidance on how to optimize the overall response time.

It is important to ensure that the web application is performing optimally, as slow page load speeds can have a negative impact on the user experience. In fact, one study by Kissmetrics found that conversion rates dropped by 40% on pages that took longer than 3 seconds to load.

Web application testing tools

  1. Cypress

Cypress is a comprehensive testing framework that allows developers to write and run tests directly in the browser. Cypress provides us with an auto-wait feature that waits for the application to finish rendering before executing the next command, eliminating the need for timeouts. Cypress also offers time-travel debugging, which allows developers to see the state of the application at any point during test execution. In addition, Cypress supports network stubbing and mocking, making it easier to test edge cases and failure scenarios.

  1. Playwright

Playwright is an open-source Node.js library for automating web browsers. One of Playwright’s best features is its cross-browser support, including Chromium, Firefox, and WebKit, which enables cross-browser testing. Playwright also offers grid capture, allowing developers to modify queries and responses as the test is being executed. In addition, Playwright supports a headless mode that allows you to run tests without a graphical user interface in the background.

  1. Katalon Studio

Katalon Studio is an open-source test automation framework that supports web, mobile app and API testing. Katalon Studio supports a visual test editor that allows non-technical users to create and run tests. It also supports keyword-based testing, allowing users to write tests using natural language syntax. In addition, it offers automatic test reporting, making it easy to track test results and identify problems.

  1. Tosca

Tosca is a test automation tool that supports end-to-end web application testing. Tosca comes with a model-based approach to testing, allowing users to create test cases without any programming skills. Tosca also offers automated risk analysis that identifies the most critical areas of the application to test. In addition, Tosca supports parallel execution, allowing users to run tests in multiple environments simultaneously.

  1. Selenium

Selenium is a popular open-source test automation tool that supports end-to-end testing of web applications. One of Selenium’s unique features is its support for multiple programming languages, including Java, Python, and Ruby. Selenium also offers auto-wait, where it waits for the application to finish rendering before executing the next command. In addition, Selenium supports test data management, allowing users to dynamically generate test data.

  1. TestComplete

TestComplete is an automated functional testing platform that allows testers to create automated tests for Microsoft Windows, Web, Android and iOS applications. TestComplete was developed by SmartBear and offers a range of advanced features such as distributed testing, parallel test execution, detailed logs and test reports, making it an excellent choice for managing complex testing scenarios. It allows you to create scripts in a variety of programming languages to create complex and customizable test cases. It also supports testing of various applications including .NET, Java, SAP, HTML5, Flash, iOS, Android and more. It also includes an object recognition engine that can accurately recognize dynamic UI elements.

Web application testing process

Testers use a web page testing approach to evaluate applications running using a web browser on the Internet. When testing a website, testers perform a set of processes before the actual testing:

Collecting requirements

In this phase, testers gather all the feature requirements and refine them and identify the gaps.

Test planning

In this phase, testers update the test plan document with a definition of the scope and objectives of the testing, the strategy, the input and output criteria for testing the site, and an evaluation of the test estimate.

Test case preparation

QA testers create test scenarios and scripts using the most appropriate automation technique, taking the testing strategy as a guide.

Execution of tests

In this phase, testers run the defined test cases and document any deviations from the planned result.

Error reporting

If a test case fails during execution and a bug is found, testers will notify and report it using a bug tracking tool such as Jira.

Repeated testing of errors

When the developer fixes the bug, the testers retest it and re-execute the failed test case.

Closure of the test

The test cycle is closed when all bugs are resolved and the web application works as expected. If this does not happen, the QA testers will repeat the process.


Web application testing is an integral part of the software development lifecycle. It is performed to ensure that all functional and non-functional requirements are met before the web application is launched to users. These tests help developers and QA engineers find gaps and bugs in the application before it is available to users, so it is an essential part of software development.

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About the author

Michaela Kojnoková

Agile Test Engineer

Po štúdiu informatiky na ŽU a TUKE som sa najviac ponorila do oblasti automatizácie testovania. Okrem toho sa venujem tvorbe webov, databázam, dátovej analytike, umelej inteligencii a strojovému učeniu. Mám rada cestovanie, šport a najviac si užívam čas strávený v prírode s mojimi blízkymi. LinkedIn

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