Cross-browser testing remains essential despite advancements in browser technology and the alignment of JavaScript engines, as browser compatibility issues persist due to differing underlying technologies and engines used by browsers like Chrome, Firefox, and Safari. The historical context of browser wars highlights how differences in adherence to standards, such as W3C guidelines, have led to compatibility challenges, particularly with legacy browsers like Internet Explorer. Cross-browser testing strategies should prioritize browsers based on target audience demographics, often leveraging tools like Google Analytics for insights. While in-house device labs are an option, cloud-based solutions like LambdaTest offer cost-effective and efficient alternatives, providing extensive browser coverage and integration with various development tools. Automation frameworks such as Selenium remain popular for their broad browser compatibility, although newer tools like Cypress offer advantages for Chrome-specific testing. Continuous testing within CI/CD pipelines and a gradual approach to expanding browser coverage are recommended, alongside maintaining manual testing practices to ensure robust web application performance across different browsers.