One size fits all! There are over 200 common screen sizes that can access the web. Responsive Design is the practice of creating a website that will render differently depending on the size of the screen on which it’s being viewed. Its purpose is to optimise the user experience. Want to see it in action? Just grab the edge of your browser and watch how the content of this page adapts as you change the size of the window.
Your website may look great on your computer, but what happens when you load it onto a smartphone? If users are forced to scroll sideways to view your pages, or can't easily access the Navigation menu, this means it's not responsively designed.
If you're not sure, simply type the full web address (including the 'http://') into the window below, and our Smartphone simulator will show how it behaves on the small screen. Alternatively, follow this link to Google's "mobile-friendly" test.