To check mobile responsive design, first open your website on different devices or use browser developer tools to simulate various screen sizes. Look for how text, images, and menus adjust when viewed on smaller screens. Tools like Google’s Mobile-Friendly Test can provide an in-depth analysis of usability. Ensure that buttons are easily clickable and content is legible without zooming. Testing on actual smartphones and tablets gives you a real-world perspective. Regular updates and adjustments are crucial to maintain responsiveness as new devices emerge. A mobile-friendly site improves user engagement and enhances search engine visibility.