JavaScript has long been a challenge for developers when ensuring cross-browser compatibility due to the unique rendering engines of different browsers, which interpret JavaScript in varied ways. Despite advancements in web technologies, JavaScript remains essential for building dynamic web applications, but it comes with common issues such as memory leaks, incorrect parameter handling, and variable scoping challenges. Developers often face problems with deprecated features in older browsers and need to utilize tools like profiling tools, linters, and transpilers like Babel to address these issues. Employing strategies such as user-agent sniffing, feature detection, and using polyfills can help in making JavaScript code work across different browser versions. Additionally, frameworks like React, Angular, and Vue.js are instrumental in overcoming cross-browser compatibility issues by providing robust solutions for building applications that function seamlessly across various browsers. The article emphasizes the importance of adopting best practices like proper code organization, naming conventions, and the use of comments to maintain code quality and functionality.