Responsive design is a popular web design strategy used by some website builders. This approach reformats the web page content to fit different screens. But in terms of search engine optimization (SEO), the search engines only care about whether a site suitably displays on mobile screens. Bing and Google have pages where you can enter your URL to see if your site functions well on mobile. Simvoly, uKit, and Weeby's strict response approach means you have no control over the mobile view. Ucraft and Wix, by contrast, offer a mobile site preview and let you make customizations that only apply to mobile viewing. For example, you may want a splash page to welcome mobile viewers or leave out an element that doesn't work well on smaller screens.