Testing web applications is essential for many reasons. Testing can aid quality control by helping identify any faults in an app's functionality or ensure it meets quality requirements. User Experience: Testing ensures the online application runs properly for users, creating an enjoyable user experience. Security: Tests make detecting web application flaws and security concerns easier so user data remains protected while protecting programs against attacks. Performance: Testing involves inspecting the web application's performance and responsiveness under different user loads and network conditions to ensure it performs optimally.