Web application testing: 6-step guide how to test a website

Web application testing

More and more web applications are being developed these days. And with each line of code being written, the potential for bugs arises.

Generally speaking, the costs of fixing bugs increase exponentially the later you find them.

The Systems Sciences Institute at IBM found that “the cost to fix an error found after product release was 4 to 5 times more than one uncovered during design, and up to 100 times more than one identified in the maintenance phase”.

And a study by the University of Cambridge found that software bugs cause economic damage of $312 billion per year worldwide

These numbers highlight the importance of finding bugs as early as possible and thoroughly testing an application before it is released.

That is where website application testing comes in.

Web app testing or application testing usually consists of multiple steps, ensuring an application is fully functional and runs smoothly and securely. It is an essential part of web development and ensures that an app runs properly before its release.

We put together a 6-step guide, which should give you an overview of what tests to run to test your app.

Let’s get started!

What is web app testing?

Website or web app testing evaluates your application or website for potential issues, defects, and bugs before it goes live and becomes available to the public.

Before you launch and test a web application or website, you must know how to test a website or web application for different types of security, functionality, performance, usability weaknesses, and bugs.

What’s the web app testing process in a nutshell?

A web testing process is a well-defined and organized method that enables QA teams to ensure fast and efficient test cases for their websites and applications.

They can rely on automation for web-based or software application testing, reducing the burden of repetitive and routine tasks.

These tests can compare real-world results with predicted ones to ensure no discrepancy.

How to test web application or website

In Software Engineering, various testing types and techniques can be employed to meet the specific demands of web testing.

These diverse approaches are instrumental in conducting comprehensive evaluations of web applications and websites, ensuring their quality, functionality, and performance align with desired standards.

Let’s start with web app.

Step 1: Functionality testing

The first step of web app testing is performed through stress testing which ensures that the functions of a system are tested. On Wikipedia, Functional Testing is described as follows:

Functional testing is a quality assurance (QA) process and a type of black-box software testing practice that bases its test cases on the specifications of the software component under test. Functions are tested by feeding them input and examining the output, and internal program structure is rarely considered (unlike white-box testing).

Functional testing happens in the source code, where the system is tested against functional requirements and specifications.

Typically, functional testing includes:

  • the identification of functions that software is supposed to do
  • data input and entry
  • the execution of the test case
  • an analysis of the actual results

During functional testing, actual operating system compatibility and usage is simulated. The idea is to come as close as possible to real system usage and create test conditions that are related to user requirements.

Testing a website can be a tedious process. That’s why it is essential to break it down into different functionalities. Your web-based testing should include testing all the links including outgoing, internal, anchor, and MailTo links. Apart from that, you should test forms to ensure they are working as intended, including scripting, default values, data, and formatting.

Testing cookies (sessions) and HTML and CSS are also essential to identify any syntax errors.

Please ensure standard compliance and test end-to-end business workflow to deliver an exceptional experience to your visitors.

Step 2: Usability testing – not only for user experience

Performing usability testing goes beyond functionality testing and combines testing for functionality and overall user experience.

Usability testing should not be mixed up with User Acceptance Testing, even though both are essential to the success of testing a web application. Each has a very different focus and is executed at different software development life cycle stages.

This can be done internally or by getting external testers that fit your potential user base. To find external testers, you can use services such as Apple’s TestFlight for applications designed for the app store.

Usability testing involves the following steps:

  1. Develop a testing strategy that ensures all functions of your application will be examined. These include navigation and content.
  2. Recruit test participants, either internally or externally.
  3. Run the test under the observation of experts.
  4. Analyze the results and improve your application accordingly.
When to do usability testing in the web application testing process flow

Step 3: Interface testing

Interface testing ensures all interactions between the web server and application server interfaces run smoothly. This includes checking the communication processes and ensuring that error messages are displayed correctly. Further things to test are that user and server interruptions are handled correctly.

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You need to test three areas: application, web, and database server. Ensure that test requests generated by test web applications are relayed correctly to the database and that the client-side output is free from errors. Apart from that, make sure the testing web server is responding to all application requests as intended, and the database is receiving the queries.

Step 4: Compatibility testing

Compatibility testing ensures that your application is compatible with all browsers and devices, a key step in web application testing.

Here are the different elements of compatibility testing when we test a web application:

Browser compatibility

Could you ensure your application functions correctly across the different browsers?

This includes checking that JavaScript, AJAX, WebSockets, browser notifications, and authentication requests are working as designed, especially if you’re using jwt authentication.

We recommend trying LambdaTest, a cross-browser testing cloud, for browser compatibility testing.

Using the Lambda tool, users can test their website on 2000+ real browsers & OS devices. 

Besides checking that your application runs in all the browsers (yes, even Internet Explorer!), you should also check it for consistency across different versions of the browsers, to see if any updates affect its functionality.

Different operating systems and their compatibility

Like with different browsers, your web application might run into problems on some operating systems. All new technologies now used in developing an app or a website may not be compatible with every operating system, including interface calls, APIs, and designs. Check that it runs smoothly on browser operating systems: Windows, macOS, Linux, and Unixes.

Web application compatibility with various operating systems is crucial for a seamless user experience on browsers operating systems. Consider the following key aspects of your operating system:

  • Windows: Ensure compatibility with different Windows versions, from Windows 7 to Windows 11.
  • macOS: Adapt to macOS guidelines and test across various versions.
  • Linux and Unix: Test on popular Linux distributions like Ubuntu, Fedora, and CentOS.
  • Mobile OS: For mobile users, ensure compatibility with Android and iOS, considering different screen sizes and input methods.
  • Cross-Browser: Test on browsers like Chrome, Firefox, Safari, Edge, and Opera for consistent performance.
  • APIs: Leverage OS-specific APIs when available, but provide fallbacks for broader compatibility.
  • Design: Tailor design elements to match the look and feel of each OS.

Addressing these factors allows your web application to cater to a diverse audience, delivering a reliable and user-friendly experience.

Mobile compatibility

These days, mobile browser compatibility testing is a given. Ensuring that your application runs on different devices and functions just as well on Android as it does on iOS is an essential part of web testing.

Step 5: Performance testing

After ensuring your application’s functionality is working correctly and responsively on all browsers and devices, it is time to test your web application and look at how it performs under heavy load.

This includes performance testing of the application under different internet speeds and how it behaves under normal and peak loads (load testing). To determine your application’s breaking point, it is under increasing stress until it ceases to function (stress testing).

In the performance testing phase, evaluating server response is crucial. Key monitoring aspects include latency, throughput, error rates, resource utilization, and response time distribution.

Efficient caching, load balancing, scalability, and failover mechanisms are vital for maintaining responsive and reliable server performance.

Analyzing server response metrics helps identify bottlenecks and ensures optimal user experiences, even under heavy loads.

Testing for resiliency is crucial to finding out how your application behaves under stress before your users do.

Please ensure you test the functionality under different scenarios and hardware configurations and that your application recovers from crashes in the best way possible.

Step 6: Security testing

After the performance testing, there is the final step of web application testing – security testing.

Security for web application testing guide ensures your web application testing guide is protected against unauthorized access and harmful actions through viruses or other malicious software.

Security testing for web applications involves the following activities:

  • Test whether secure pages can be accessed without authorization
  • Check that open sessions are closed after ongoing user inactivity
  • Verify the application’s SSL
  • Make sure that restricted files cannot be downloaded without proper authorization

Overall, a security testing checklist comes in handy at this stage, as it helps you to structure and organize your testing efforts. Such a checklist should include tasks in the following areas:

  • Secure Transmission
  • Authentication
  • Session Management
  • Authorization
  • Cryptography
  • Data Validation
  • Denial of Service
  • Specific Functionality Tests
  • Error Handling

Some of the specific tests that you should perform include the following:

  • Test by copying and pasting the internal URL into the browser address bar without login to check whether internal pages open without credentials.
  • If you are logged in using your credentials and exploring internal pages, then attempt to modify URL options directly. This should be denied right away.
  • Try typing in a few invalid inputs in input fields like username, password, contact number, address, etc. See how the website responds to invalid inputs.
  • No user should be able to access any web directory or file without the download option.
  • Verify the CAPTCHA for automating script logins.
  • Verify whether SSL is being used for web security. If yes, an adequate message should be communicated to the users when they go from non-secure HTTP:// pages to secure HTTPS:// pages and vice versa.
  • Every transaction, error message, and security breach attempt should be recorded in log files.

Additional test scenarios


Crowd testing expands the testing horizon by harnessing the power of a diverse and dynamic crowd of testers to evaluate your web application.

This approach leverages a large and geographically dispersed group of testers, often called a “crowd,” to uncover issues across various devices, browsers, and user scenarios.

Crowdtesting for your product

Crowd testing should be distinct from Usability Testing or User Acceptance Testing, even though they all contribute significantly to a web application’s success. Each type of testing has a distinct focus and is typically carried out at different phases of the software development life cycle.

Here’s how you can prepare for crowd-testing:

  • Define testing objectives – Clearly outline your testing goals, specifying areas that require evaluation.
  • Choose a crowd-testing platform – Select a reliable platform or service provider with access to diverse testers.
  • Design testing scenarios – Develop scenarios covering your application’s functionality and real-world usage.
  • Recruit a diverse crowd – Engage testers representing your target user base with various devices and browsers.
  • Execute tests and monitor – Distribute test scenarios, monitor the testing process, and ensure thorough documentation.
  • Collect and analyze findings – Gather test reports and analyze results to identify defects and areas for improvement.
  • Iterate and improve – Make necessary improvements based on feedback, creating a refined web application.

By following these steps, you can effectively harness the collective wisdom and diverse perspectives of a crowd of testers to enhance the quality and performance of your web application.

Crowdtesting with Usersnap

Database testing

The database is a pivotal and intricate component within your web application, necessitating meticulous testing procedures.

This multifaceted testing process involves various critical activities to guarantee the database’s reliability and performance.

Query execution verification

The first imperative task is to examine the execution of queries meticulously.

This is just to confirm that no errors arise during the process. Any query errors can lead to significant malfunctions in your web application, making this a fundamental aspect of database testing.

Data integrity assurance

The integrity of data within the database is paramount. As data continually flows in, gets updated, and occasionally deleted, it’s essential to verify that the database maintains data integrity throughout these operations.

Ensuring data consistency, accuracy, and adherence to defined rules and constraints is crucial to maintaining the overall quality of your web application.

Query response time assessment

Database performance directly impacts the user experience. Hence, assessing the response times of queries is a key task.

Monitoring query execution times and identifying bottlenecks allows you to optimize queries as needed. This optimization ensures that your web application remains responsive and efficient, even under heavy loads.

Presentation validation

Finally, the database’s role in delivering data to your web application’s interface is crucial. It’s essential to validate that your web application’s data retrieved from the database is accurately presented.

Any discrepancies in user data or inconsistencies in data presentation can lead to user clarity and trust.

Database testing is a comprehensive process that thoroughly scrutinizes query execution, data integrity, performance, and data presentation. These efforts ensure your web application functions reliably and delivers a seamless user experience.

By conducting rigorous database testing, you can identify and address potential issues before they impact your users, ultimately enhancing the overall quality of your web application.

What are some types of web testing?

There are different types of web testing, including the following test cases:

Simple static website testing

It shows the same content to every visitor regardless of when and from where they visit the website. These types of websites are often informational and don’t offer a lot of functionality or interactive experience.

Dynamic website/application testing (CMS)

This is the type of website where the user can change and update the content regularly. These are more complex to test as they also have a backend programming language like PHP or ASP, database, and scripting languages.

E-commerce website

These are a type of dynamic, website testing where the application’s primary purpose is to deliver a shopping experience. In this type of web testing, the most crucial part is to ensure that the transactional process is functional end-to-end.

Mobile website

It is important to carry out full and automated web testing of your mobile website as more than half of the visitors come from a mobile device. The web testing needs to ensure the mobile website is properly responsive without any broken experiential occurrences.

Testing tools for web application development

In web application development, testing is pivotal in ensuring your application functions correctly, performs well, and delivers a seamless user experience.

To streamline the testing process and improve the efficiency of your development cycle, it’s essential to leverage a range of testing tools.

Here, we’ll explore some of the key categories of testing tools that can enhance your web application development workflow:

1. Automated testing tools

Automated testing tools are indispensable for performing repetitive and systematic tests, ensuring your web application remains functional and free of regressions throughout development.

Some popular automated testing tools include:

  • Selenium: Selenium is a versatile tool for automating browser interactions, supporting various programming languages and browsers. It’s widely used for functional and regression testing.
  • Cypress: Cypress is a modern end-to-end testing framework designed for web applications. It offers real-time reloading and a robust debugging experience.
  • Jest: Primarily used for JavaScript-based applications, Jest is a testing framework emphasizing simplicity and speed. It’s commonly used for unit and component testing.

2. Load testing tools

Load testing tools help assess how your web application performs under different user traffic and stress levels.

These tools are crucial for identifying performance bottlenecks and ensuring your application can handle peak loads. Notable load testing tools include:

  • Apache JMeter: JMeter is an open-source tool for load and performance testing, capable of simulating various scenarios and load levels.
  • LoadRunner: LoadRunner, developed by Micro Focus, is a comprehensive performance testing tool that offers a wide array of protocols and integration capabilities.
  • Gatling: Gatling is a highly scalable and open-source load testing tool that uses the Scala programming language for scripting realistic scenarios.

3. Security testing tools

Security is paramount in web application development. Security testing tools help identify vulnerabilities and weaknesses that malicious actors could exploit. Some prominent security testing tools include:

  • OWASP ZAP: The OWASP Zed Attack Proxy (ZAP) is a widely-used open-source security testing tool that helps find security vulnerabilities during development and testing.
  • Burp Suite: Burp Suite is a powerful suite of tools for web application security testing. It includes features for scanning, crawling, and exploiting vulnerabilities.
  • Nessus: Nessus is a network vulnerability scanner that can also be used to identify security issues in web applications.

4. Cross-Browser Testing Tools

Cross-browser testing tools help ensure your web application looks and functions consistently across different browsers and versions. Popular options include:

  • BrowserStack: BrowserStack provides a cloud-based platform for testing web applications on various browsers and devices.
  • CrossBrowserTesting: CrossBrowserTesting offers real-time testing of web applications on a wide range of browsers, including mobile devices.
  • Sauce Labs: Sauce Labs provides a cloud-based testing platform for automated cross-browser testing.

5. Accessibility testing tools

Accessibility testing tools help ensure that your web application is usable by people with disabilities. They identify issues related to accessibility compliance. Some notable tools are:

  • axe: axe is an open-source accessibility testing engine that integrates with various testing frameworks and provides actionable accessibility feedback.
  • WAVE: The Web Accessibility Evaluation Tool (WAVE) is a browser extension that provides instant accessibility analysis of web pages.
  • Pa11y: Pa11y is a command-line tool that helps automate accessibility testing and provides reports on issues.

6. Code quality and continuous integration tools

While not exclusive to testing, code quality, and continuous integration tools play a vital role in maintaining the overall health of your web application. Popular tools in this category include:

  • Jenkins: Jenkins is an open-source automation server that supports building, deploying, and automating various aspects of software development, including testing.
  • Travis CI: Travis CI is a cloud-based continuous integration service that automates the testing and deployment of your code.
  • CircleCI: CircleCI is another popular continuous integration and continuous delivery (CI/CD) platform facilitates automated testing.

By incorporating these testing tools into your web application development workflow, you can enhance your application’s quality, security, and performance while accelerating the development process.

Choosing the right tools and strategies based on your project’s specific requirements can significantly contribute to the success of your web application.

Wrapping it up

So, these were the six different tool types of web application testing. Following the main steps thoroughly before rolling out and testing your web application should go a long way in finding any bugs and errors and enable you to fix them before it’s too late.

Simple website tester: Usersnap

If you’re looking for an uncomplicated yet effective way to test your website, Usersnap is the answer.

This user-friendly tool simplifies website testing, allowing you to capture screenshots, annotate them, and highlight issues effortlessly. 

With Usersnap, you can streamline communication among team members, making it easy to spot and address bugs, usability concerns, or design glitches.

This straightforward approach to website testing ensures you can quickly gather valuable feedback, enabling prompt improvements to enhance your web project’s overall quality and user satisfaction.

It saves time, ensures accuracy, and boosts developer productivity.

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And if you’re ready to try out a visual bug tracking and feedback solution, Usersnap offers a free trial. Sign up today or book a demo with our feedback specialists.