16 Web Application Testing Challenges Faced by Testers

Cross Browser Compatibility

Earlier, when internet explorer was the only browser available, just unit testing would have done the job. But, currently, with hundreds of browsers along with their different versions available for desktop and mobile, cross-browser compatibility is a common issue. It is ideal for a tester to use a cloud testing platform like TestMu AI for testing whether the application is compatible across different browsers.

Key Takeaway: Testing a web application on Chrome, Firefox, Safari, and Edge, including their mobile versions, catches rendering and script errors that a single browser never exposes.

Responsiveness

The one thing to look out for while testing is whether the application fits properly in the device resolution. A tester must check if there are any horizontal scrolling, alignment or padding issues, and sizes of font and buttons in different devices.

It’s of utmost importance that your images are responsive to different resolutions. In this case use LT Browser a dev-friendly browser for mobile view debugging on which you can see the mobile view of your website on Android and iOS resolutions.

Key Takeaway: Responsive checks cover horizontal scrolling, alignment, padding, and font and button sizing at real Android and iOS screen resolutions.

Cross-Device Compatibility

Nowadays, people mostly use mobile devices to access websites. Although there are a limited number of devices in iOS, the count increases tenfold when it comes to Android. It is important for a tester to target the devices where the application is meant to run and start testing in each of them.

Key Takeaway: Android device fragmentation turns device coverage into a selection problem, so testers target the specific devices the web application is built for.

Integration Testing

The rating of an application depends on its usability as well as functionality. Integration testing is a must thing to carry out at the user’s end to check whether the application is reliable, all the critical functionalities work properly as well as there is no significant impact on performance after merging new features.

Key Takeaway: Integration testing after a feature merge confirms that critical web application functionality still works and that performance has not dropped.

Security

If the application has features like online transaction and payment gateways, security testing should be executed to ensure that there are no chance of any fraudulent activities and local storage of payment-related data in the device.

Key Takeaway: Security testing of a web application covers online transactions, payment gateways, and payment data written to local storage on the device.

Performance Testing

Often a web application gets too slow or crashes when the internet traffic increases all of a sudden. Performance testing should be carried out to ensure that there is no impact on the speed of performing an activity using the application.

Key Takeaway: Performance testing shows whether a web application holds its response time when internet traffic rises suddenly.

How Do AI Agents Change Web Application Testing?

AI agents now write, run, and repair web tests from plain English steps, which cuts selector maintenance and moves the tester job towards reviewing what the agent decided.

The change is practical rather than total. Agents remove repetitive authoring work, while test design, risk selection, and the definition of correct behavior stay with the tester.

• Test authoring: an agent turns a step such as log in and check the cart total into Playwright or Selenium code and runs it against a real browser.
• Locator repair: self healing locators re-bind a broken selector to the same element after a DOM change, which removes a share of false failures.
• Browser control: the Model Context Protocol and the Playwright MCP server let a model drive a live Chrome session and read the accessibility tree instead of screenshots.
• Failure triage: an agent groups repeated failures by cause and flags flaky tests that pass and fail on the same commit.

The limits matter as much as the gains. An agent can confirm that a checkout page loads and still miss a wrong price, because correctness depends on a business rule that is not visible in the rendered DOM.

Security and accessibility results need the same caution. A passing color contrast check does not prove that a screen reader user can finish a purchase.

Treat agent output as a first draft. Review every generated assertion, keep production test data out of prompts, and pin the browser version the agent runs against so results stay reproducible.

Key Takeaway: AI agents cut web test authoring and locator maintenance, but a human still defines correct behavior and reviews security and accessibility results.

Application Getting Slow

It does not matter what device is used to access the application, due to poor network coverage or low configuration of processor or physical memory an application may run slower or take an infinite time to load a page. Testing should be conducted to ensure that it is properly optimized to run properly under any condition.

Key Takeaway: Poor network coverage and low device processor or memory configuration slow a web application, so optimization has to be verified under weak conditions.

Usability Testing

Interactive and dynamic web applications are always popular among users. Proper usability testing should be carried out across devices from the user’s perspective to ensure there are no such issues that may impact the usability of the application.

Key Takeaway: Usability testing from the user perspective on real devices exposes interaction problems that functional test cases pass over.

Entry and Exit Points

There are stages when a user will need to navigate out from the application to a third-party website and redirect from another website or gateway to the application. It is a real challenge to test whether this feature works properly.

Key Takeaway: Redirects between a web application and third party sites or payment gateways need explicit test cases in both directions.

Checking the Standards and Compliance

W3C has stated several standards and guidelines that every web application must comply to. To ensure proper site ranking in the search engine index, the code should be tested properly to check whether the website follows those standards and guidelines.

Key Takeaway: W3C standards compliance in the markup supports correct indexing of a web application by search engines.

Firewalls

Often a web application is blocked by certain firewalls or port. This may be because of the security certificate or something else. Testing should be conducted to ensure that it behaves properly across all firewalls.

Key Takeaway: Firewall and port blocking, often caused by a security certificate problem, needs testing from networks outside the development environment.

Accessibility Testing

W3C has mentioned several guidelines stated in Section 508 and WCAG which requires a website to be accessible by all people, especially people with disabilities. Accessibility testing should be conducted to ensure that users with hearing or sight disabilities can access the website with the use of screen-reader and other devices.

Key Takeaway: Accessibility testing against WCAG and Section 508 confirms that screen reader users can complete tasks in a web application.

Project Deadline

Testing is often not conducted properly when a project is coming nearer to the deadline. It should be planned beforehand to ensure that there is a proper time for testing the functionality, performance, and usability of the application before it is deployed in production.

Key Takeaway: Test time planned at the start of a project protects functionality, performance, and usability checks from being cut before release.

User Experience

Users love an application not only based on its functionality. But also on how great it is to use. Testers must check the overall design and user experience of the application to ensure that the user gets attracted and engaged while using it.

Key Takeaway: Design and interaction review sits alongside functional testing because users judge a web application on how it feels to use.

Web Service Requests

All the latest web applications are integrated with web service layers like SOAP/JSON/XML, etc. The requests sent by those web services contain certain parameter values that need to be tested. This testing is particularly important if your web application has a Google Map API integrated with it.

Key Takeaway: Web service layers such as SOAP, JSON, and XML carry parameter values that need their own test cases, including third party APIs like Google Maps.

User Input Validation

This is an important part often skipped during testing. Web applications may often feature forms to be filled up by users. Testing should be conducted to ensure that there are proper validation rules and in case of wrong input, the user is warned and further proceeding with the form submission is blocked until the input is corrected.

That’s all from our side. Always remember to test the above-mentioned facts carefully before your website is launched. Do let us know if you have faced any other challenges while testing your web application.

Now start your free web testing on the world’s fastest testing platform.

Key Takeaway: Form validation rules must reject wrong input, warn the user, and block submission until the input is corrected.