Which aspect is crucial for effective mobile SEO?

Responsive design to fit different screen sizes is crucial for effective mobile SEO because it ensures that a website displays correctly on various devices, including smartphones and tablets. This adaptation enhances user experience by providing a seamless and optimized viewing experience, regardless of the device being used. Since mobile users often have different needs and are in different contexts compared to desktop users, a responsive design allows the content layout, images, and functionalities to adjust according to the screen size.

Incorporating responsive design not only meets the requirements of search engines like Google, which prioritize mobile-friendly sites in their rankings, but also helps retain visitors by providing them with an accessible interface. Since mobile traffic constitutes a significant portion of overall internet usage, having a responsive design directly influences both user engagement and overall search performance.