Web Application Testing: The Ultimate Step-by-Step Guide

Written by Harsh Vijay
Published on September 7th, 2022

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Even if you create the most extravagant web application, there are still chances that it might not work the way you want. And the irony is that most website owners aren't aware of what's going wrong.

Maybe the design is unappealing? Or is the performance of the website bad? Or maybe it's difficult to navigate through? You will never know until you perform complete web application testing.

The internet doesn't give out second chances. Not testing your websites for bugs and errors can lead to 88% of your users churning out of your web application.

Here, the trick is to follow the correct process and use the right tools. This approach has helped our users test over 360 web applications in the last year.

This blog will talk in detail about web application testing, its process, and the best web testing tools that you can use to improve the quality of your web application.

What is web application testing?

A web application is a package of client-side code built on various layers of interdependent modules and core web technologies like HTML, CSS, and Javascript. And, with each line of code added, the chances of bugs increase.

This is where web application testing helps.

Web application testing is a practice that ensures that the quality of the developed tool is similar to what you intended to build. It tests your web application on performance, operating system compatibility, browser compatibility, security, functionality, user experience, and usability in various environments.

Ideally, website testing is done before launching the product, but it's also helpful in finding errors, bugs, or oversight mistakes that might have gone undiscovered during the development phase.

Testing is a crucial part of software development. Even the slightest change in code can cause unwanted errors.

Benefits of web application testing

Thousands of web applications are built every day. We have reached a point where there is a web app for everything. Users today are particular about the type of application they want to consume and the features they are looking for. An indifference to experience can lead to them churning off.

That's why doing regular web application testing is essential; here are some benefits-

  • Web applications remove bugs and errors, leading to increased website performance and a high threshold of user load.
  • Testing saves your business time and money that you might have lost in fixing bugs. According to the Systems Sciences Institute, "The cost of fixing 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." This highlights the importance of web testing and getting your errors fixed as soon as possible.
  • Regular web application testing ensures that all web features work smoothly and that your app logic works fine.
  • Testing helps deliver an error-free website, which is extremely important for a high user experience.
  • Website testing removes the need to continuously redesign your website. It ensures that your web app's interface remains fresh and up to the mark.

How to do website testing?

A web application is built from thousands of lines of code and requires rigorous testing. If performed manually, it can take days or even months to evaluate the website on all parameters and on different database servers. That's why all QA teams use automation to get testing done faster.

Test automation removes unnecessary routine and repetitive tasks from humans and gets them done by machines. It delivers higher accuracy than manual testing and frees up time and resources that manual testing will cost while getting your website tested by humans.

There are three different levels of web testing-

Level 1: Unit testing

This tests individual units or groups of units of code in a web application. Unit codes are closely tied to software development. Testing these ensures that the piece of code in the software is working as intended.

Level 2: Integration testing

Integration tests check that the code units interact smoothly with external components like databases, REST APIs, and more. It's like testing communication between two parts irrespective of their internal workings for the user. The tester at this level provides the input and tests the output.

Level 3: End-to-end testing

End-to-testing is the final level of testing that encounters problems in the software, user interface, and user interaction with the app. This process is quite extensive and is performed cross-browser and across multiple database servers.

Each level contains various website testing techniques, which we will explain in our next section.

What should I test in web testing?

There are a number of web app tests that you can run to ensure quality website performance -

  • Functionality testing: This ensures that all features of your website are working fine.
  • Usability testing: This measures how simple your web application is to use.
  • Interface testing: This verifies seamless communication between two unique software systems.
  • Compatibility testing: This checks that your web application works appropriately across various web servers, operating systems, mobile devices, and database servers.
  • Performance testing: This tests your web application's speed and efficiency in completing processes.
  • Security Testing: This assesses your web application to discover vulnerabilities and loopholes responsible for data breaches and security attacks.
  • Crowd testing: This measures the performance of your web application when used by real people.

9 best types of web testing

Now, let's start to understand the various types of web application testing you can implement to make your platform error-free. Some of them can feel a bit technical, but most of them you can do with your team.

1. Functional testing

Functional testing evaluates the web app's functionality on whether the features work. This means testing workflows, looking for broken links, assessing database connections, and ensuring a smooth user interface.

Functionality testing is mainly a black-box testing method that tests the functions of an application without looking into its internal structures or codes. The testing starts with feeding inputs to figure out the errors in the output. The result is crucial in understanding what's going wrong and how you can improve it.

There are four types of functional testing, including-

  • Sanity testing: It checks whether the output of the process is rational and can possibly be true.
  • Smoke testing: This tests whether your web application is stable or not.
  • Regression testing: It ensures that your web app still works well even after updates, code changes, and improvements.
  • User acceptance testing: This step assesses if all features work as intended for the end user.

How to perform website functionality testing?

  1. Identify the function that needs to be tested.
  2. Create input data based on the function.
  3. Determine the output for the input data according to the function
  4. Execute the test
  5. Measure the difference between the actual and predetermined output You can now make the necessary changes to make the output data similar to what you expected at first.

2. Usability testing

Today's customers demand a flawless website that's easy to use with modern design elements. So, when testing a web application, it's crucial to evaluate both the user interface and the user experience. Usability testing is done by real-time users to observe and discover issues that people familiar with can no longer identify.

There are a number of benefits to website usability testing-

  • It validates your prototype and gives real users a reaction after using your product.
  • Usability testing ensures a premium user experience through testing whether the web app works as intended.
  • It helps identify complex flows that make your web app difficult to use and navigate.
  • Usability testing helps identify minor errors like broken links, grammatical issues, and site errors that developers might have missed out on.

How to perform usability testing?

  1. Start by identifying the problems you want to focus on, the types of users you want to test, and the questions you want to ask your users.
  2. There are a number of methods to conduct usability testing: remote, in-person, moderated, un-moderated, self-explorative, and comparative. Decide which one you think would salvage your usability requirements.
  3. Now recruit participants through your website, agency, or social media or request clients for usability testing.
  4. Design tasks that you want your participants to perform on your web app. For instance, an e-commerce website can ask users to select a product and get it through the checkout.
  5. Note down the time taken by users to complete the task. This step is extremely crucial to identify if there are any complex flows, usability problems, or lack of user experience.

3. Interface testing

Interface testing is similar to software testing, which ensures proper connectivity between two software systems. This includes two major tests: application server and database server interface, and web server and application server interface.

Interface testing ensures that the end user does not face any hindrance while using the particular software. Developers mostly do interface testing on the messaging layer of the system; they conduct functional, load, and security tests on each code unit.

Running frequent interface testing is beneficial for your web application because-

  • Identify areas that are frequently used by the users and check their user-friendliness.
  • It helps understand the behavior of the application in the case of network or web server issues.
  • Interface testing keeps the security policies of the application in place and ensures robust communication between various components.
  • It checks web applications for proper server execution.

How to perform interface testing?

  1. Start by defining your requirements, like the test's purpose and the functions and features you want to evaluate.
  2. Now that you know your evaluation areas, it's time to finalize what output you are expecting from this test. Discuss with your developers and define the expected outcome.
  3. Start with small codes and functions to assess if the final output matches the expected return.
  4. Evaluate the performance of your application by deciding on a start and end point. Measure the expected time of interface testing with the actual time taken. You can then discuss with your developers how you can improve to minimize this deviation.

4. Compatibility Testing

Compatibility testing is non-functional testing that assesses your web application on various platforms and environments. Developers must ensure that your developed application works for all devices, hardware platforms, browsers, and software. This testing ensures that your application can seamlessly work across browsers without any trouble.

Types of compatibility testing

  • Hardware: Check hardware compatibility with RAM, ROM, Hard Disk, Memory Cards, Processor and Graphics Card.
  • Network: Check the web application's performance on a network with varying bandwidth, operating system, and capacity.
  • Smartphones: Check compatibility with mobile devices with different operating systems like Android, iOS, Windows, etc.
  • Operating system: Check compatibility with different operating systems like Windows, Mac, Unix etc.
  • Browser compatibility testing: Check browser compatibility of your web app with different browsers like Google Chrome, Firefox, etc.
  • Software: Check compatibility with various software and their versions.
  • Devices: Check compatibility with various devices like Bluetooth, USB ports, scanners, etc.

How to perform compatibility testing?

  1. Define the set of platforms or test environments in which the application is expected to run.
  2. Note the expected outcome of this compatibility testing by collaborating with your developer.
  3. You can then check the web application on all platforms, devices, and environments and further evaluate its performance.
  4. Report the bugs, fix them, and rerun the test. The end-to-end workflow of the application should be smooth, stable, and error-free before handing it to the customers.

5. Database Testing

Database testing refers to software testing that checks for tables, schemas, and triggers in the database. As the complexity of your application increases, the need for frequent database testing increases. Developers use database testing to check web applications' performance on complex queries under load tests.

What to test in database testing?

  • Transactions: When testing transactions, your database should satisfy the ACID (Atomicity, Consistency, Isolation, and Durability) properties.
  • Database Scheme: It refers to how data will be organized in your database.
  • Triggers: When a certain event takes place, your database should automatically trigger the piece of code that needs to be executed.
  • Field constraints: Check whether the default value of a field is accurate. Field constraints specify the rules of data governing a field. You must have a value for this in your database.
  • Stored procedures: These are user-evoked functions where developers assess that the results are similar to the expected value.

How to perform database testing?

  1. Prepare the environments that the application is expected to work in.
  2. Note the expected outcome of this database testing by collaborating with your developer. Ensure your developer is well-versed in the knowledge of SQL and DML (Data Manipulation Language) statements.
  3. You can then check the web application on all platforms, devices, and environments and further evaluate its performance.
  4. Report the bugs, fix them, and rerun the test.

6. Performance Testing

Performance testing checks your web application for speed, stability, response time, reliability, and scalability. Performance testing aims to ensure a premium user experience and discover bottlenecks that affect web performance. An ideal web app should respond quickly, manage maximum user loads, and remain stable in all circumstances.

Types of performance testing

  • Load testing: Checks your application's ability during normal and peak loads.
  • Spike testing: Tests software's reaction to sudden changes in user load.
  • Stress testing: Tests your application in extreme workloads like high load or complex data processing to identify its breaking point.
  • Endurance testing: This ensures that the application can pass the anticipated load test for the maximum time.
  • Volume testing: This tests the web app's performance under various database volumes.
  • Scalability test: Ensures the ability of the application to effectively scale without downgrading user experience.

How to perform performance testing?

  1. Determine your web app's testing and production environments. Also, understand your web app's hardware, software, and other network configuration to help developers lay out effective performance tests.
  2. Plan your test scenarios. For instance, what will happen if there are a certain number of users on the site at the same time. Create similar scenarios to better test the performance of your web app.
  3. Identify web performance metrics like response time, wait time, average load time, requests per second, error rate, transactions failed or passed, and others to plan your expected results.
  4. Run the test and analyze the results. Make changes to the app till it offers speed, stability, and scalability.

7. Security testing

Security testing assesses your web application for flaws, vulnerabilities, and loopholes to prevent it from malware, cyberattacks, and data breaches. It ensures that the unauthorized data remains confidential and is limited to individuals/ entities with access. Security testing checks your application for -

  • Vulnerability: It is a security risk that hackers can exploit to gain access to your app data.
  • URL manipulation: Also called URL rewriting, it alters client-browser communication to hack crucial data and credentials.
  • Spoofing: It is the creation of fake look-alike websites and emails to trick the user into clicking some malicious email attachments.
  • SQL injection: This refers to injecting malicious SQL codes into entry fields to access user information.
  • XSS: Also called cross-site scripting to insert malicious JavaScript codes to otherwise safe websites.

How to perform security testing?

  1. Determine your application's security areas that you want to include in the test.
  2. Check whether your application's assets are updated to a newer version, follow user permission roles, and maintain security protocols.
  3. Ask your developer to conduct penetration tests, configuration tests, client-side logic, database security, network assets, input validation and authentication tests.
  4. Document website vulnerability details. Discuss potential solutions for security fixes with your developer. Make changes and ask a reputed vendor for a Vulnerability Assessment and Penetration Testing (VAPT) certificate.

8. Regression Testing

Regression testing ensures that any changes in a program or code haven't negatively affected the performance of the existing features. It retests the already executed code to see if it works fine. Code changes often result in defects and malfunctions in the app; thus, frequent regression testing is responsible for maintaining your web app's stability.

Various regression techniques that you can employ are -

  • Unit regression testing: This is done during the unit testing phase, where any dependencies on the unit code are blocked so that they can be tested individually.
  • Partial regression: This verifies whether the code works fine after the changes are made by integrating it with already existing or unchanged code.
  • Complete regression: This is done when changes are made in multiple modules and to check their impact on other unchanged modules.

How to perform regression testing?

  1. Define your regression testing method, retest all, regression test selection ( only perform tests on the selected text-suite), test case prioritization ( select test case with the highest priority is executed first) or hybrid (select specific test suite depending on its priority).
  2. Select the test suite according to the changes made and their priority in the app.
  3. Determine the estimated result or required eligibility to pass/fail the regression test.
  4. Try automating tests for faster and more reliable outcomes. Most developers use QTP, Selenium, Watir or others to automate the process.
  5. Analyze the regression test report and make adequate changes.

9. Crowd testing

Crowd testing, or crowdsourced testing, involves getting your web application tested by real users on different devices across the globe to identify bugs and errors. In-house developers can solve high-level bugs, but to expect that they can test applications on all devices and discover every potential error is impossible.

If your in-house team struggles to find enough time for testing before the product launch, you should definitely opt for crowd testing. There are a number of benefits to doing this type of testing-

  • Crowd testing is affordable since the testers are paid for the quality they deliver. So, if they do not provide the expected output delivery, their payment is also nil. It is 50-70% cheapr than other testing methods and can deliver similar results in half the time.
  • Through crowd testing, you get candid feedback from customers at different locations using different browsers and mobile devices, which is impossible in manual testing.
  • More crowd testers means more diversity of thoughts and faster feedback. It can 4x the market speed and make you ahead of your competitors.
  • It offers more insight than an internal team could come up with.

How to perform crowd testing?

  1. Define the scope of your crowd testing, like a finished product or a particular feature, or test your app's beta version.
  2. Decide your requirements based on what you want to achieve through this test, the expertise level of your testers, and the timeline for completion.
  3. Hire your testers from renowned crowd testing companies like Testlio, Digivante, Global App Testing, Test IO, Cobalt and other popular ones.
  4. Communicate with the testers about your expectations and what you want them to do. Educate them on how to make a bug report and the testing methods to adopt.
  5. Initiate the test by setting up secured access for your testers using relevant mobile applications and operating systems.
  6. Complete the testing process and evaluate the data collected. Make changes and repeat the process to achieve the expected outcome.

6 best tools for Website Testing

1. ruttl

ruttl is one of the best web testing tools on the market, with advanced issue tracking features and visual tests that let you identify bugs in seconds. It's super-easy to install; users just have to download the Google extension, and they can start adding websites within seconds. ruttl is like a sticky note on a webpage. Anyone involved in the website's development process can use it for bug tracking.


  • Provide contextual feedback by leaving comments on the elements and not on the location.
  • It's a one-click process that doesn't require any technical expertise.
  • Perform seamless navigation on everything- menus, buttons.
  • Collaborate with your team by simply adding emails to a project.
  • Raise tickets to point out bugs and share them with your team.
  • ruttl offers integration with over 3000+ tools using Zapier.
  • The easiest way to get unfiltered customer feedback for your staging projects.
  • No signup is needed for client comments.
  • You can ask customers to review web pages, web apps, images, and PDFs.
  • Get feedback on your web apps on ruttl.
  • Integrate with Slack to get instant notifications about client feedback through Slack.
  • Make instant real-time changes on your webpage through ruttl.
  • You can check all your website edits, comments made, and content changed on web pages from the activity panel.
  • Commendable customer support on all channels-Slack, email, in-app feedback button, and live chat.

Pricing: ruttl offers a bug tracking feature at just $33/month, along with some amazing features.

Signup and join the 15000+ teams and freelancers that use ruttl daily as their bug tracking tool.

2. BrowserStack

BrowserStack is a cloud-based online testing platform that tests your web applications on different mobile devices and multiple browsers without using devices, emulators, or virtual machines. It has zero setup and maintenance costs with instant access to over 3000+ browsers, Android and iOs users.

Features of BrowserStack -

  • It allows cross-browser testing on internal dev and staging environments, various browsers, and devices to help discuss even the tiniest issues.
  • BrowserStack offers automated visual testing to help discover bugs before your users do.
  • Besides web application testing, you can also test your mobile apps on real mobile devices and debug your software instantly.
  • You can seamlessly integrate BrowserStack with Selenium, Jenkins, Slack, and Gitlab. Jira and many other tools.


BrowserStack offers four paid plans starting at $39/month/user. You can use their free trial before committing to the tool.

3. Selenium

Selenium is a testing tool that automates web applications for testing purposes. It is not a single tool and offers a suite of testing tools like Selenium WebDriver, Selenium IDE, and Selenium Grid. Selenium Webdriver allows for cross-browser testing, while Selenium IDE is a tool for developing automated test cases for web applications. Selenium Grid lets you run tests on several machines in various environments.

Features of Selenium-

  • Selenium is a portable, open-source website testing framework that helps with faster testing.
  • Selenium supports various operating systems like Linux, MS Windows, and Macintosh to conduct testing.
  • Developers can conduct various tests like functional, regression, data-driven, and batch testing.
  • It supports various browsers like Mozilla Firefox, Opera, MS Edge, and Google Chrome to conduct testing.


Selenium is free to download from their website, but there are a number of additional costs that you might have to pay.

4. TestCafe

TestCafe offers end-to-end testing without the need for WebDriver and manual timeouts. Since it runs on Node.js and browsers, you already have it. This open-source platform allows you to create, run, and automate tests without coding. TestCafe is a dedicated tool for developers and QA teams who want to simplify the testing process.

Features of TestCafe

  • TestCafe Studio’s Visual Test Recorder observes your actions as you navigate the web page and automatically generates steps. These steps can be used to quickly test web pages across different mobile, desktop, and cloud browsers.
  • TestCafe auto-generates selectors for every page element in the test, which usually takes a lot of time in manual testing.
  • It is a cross-platform and cross-browser application that works well with Windows, Linux, and macOS.
  • TestCafe does not require any third-party integrations or Selenium/WebDriver. Users can start testing as soon as the product is installed.


TestCafe is free and open-source and is available for anyone to use.

5. TestComplete

TestComplete is a GUI testing tool that lets you easily test every web, desktop, and mobile application. It offers an intelligent object repository that supports more than 500 controls and makes sure the GUI tests are robust, scalable, and easy to maintain. You can perform a number of tests like keyword, scripting, test recording and playback, data-driven, and test visualizer.

Features of TestComplete

  • Record your tests to create automated UI tests across web, desktop, and mobile applications.
  • Get real-time information on your tests through a single-unified dashboard and track their progress.
  • TestComplete offers free training and support to help all customers with testing.
  • You can integrate TestComplete with your DevOps to ensure continuous testing.


TestComplete offers two paid plans starting at $3260/month.

Final thoughts

Frequent web application testing is extremely crucial for developers and QA engineers to detect bugs and errors that might negatively affect customer experience. It also gives you an overall idea of how your website performs, its strengths, and its weaknesses. There are several web testing methods to check your website's performance.

You can use tools like ruttl to identify and communicate visual bugs and errors in your web app with your team before it gets to your users.

20,000+ companies are using ruttl to save time and money on their projectsstock images of people in a row