The article delves into the challenges and solutions associated with achieving cross-browser compatibility for JavaScript on modern websites. It highlights JavaScript's integral role in creating interactive applications but notes that varying browser support presents a significant hurdle for developers. Common issues such as incorrect DOCTYPEs, vendor-specific styling, and outdated browsers contribute to these challenges. The article suggests using tools like linters and browser developer tools to identify and resolve errors, while emphasizing the importance of feature detection, libraries, and polyfills to enhance compatibility. It also discusses the practice of JavaScript transpiling to ensure modern features work across older browsers. Ultimately, the article stresses the necessity of cross-browser compatibility as an essential aspect of development, equating its importance with styling and scripting, to ensure applications perform consistently across different platforms.