Cross-browser compatibility is a critical aspect of web development, ensuring that a website appears consistent across various browsers and devices, which is particularly challenging due to the multitude of browsers and mobile devices available. Joomla, a popular open-source content management system, is highlighted as an effective tool for creating dynamic websites without requiring advanced web development skills. The process involves downloading Joomla, setting up a project, and running applications using PHP. Once a Joomla-based application is developed, thorough testing across major browsers and devices is essential to identify and fix any UI or functionality issues, often requiring specific CSS adjustments or version upgrades. Common issues include responsiveness problems due to varying device specifications and browser support limitations, particularly with older versions of Internet Explorer. The article also suggests using tools like LambdaTest to facilitate extensive cross-browser testing across numerous browser versions, ultimately positioning Joomla as a versatile solution for developing responsive, cross-browser-compatible websites.