How to Change a Background Dynamically in a Website. Using CSS and JavaScript, you can dynamically change the background on your website.

Add a short CSS class to an HTML Web page to use animated and stationary GIF images as the page's background.

Google says images styled with CSS won’t be indexed in Image Search, advising developers to use HTML tags for important visuals.

Google's John Mueller reminded us that when it comes to your CSS background images, Google won't be indexing or ranking those images in image search. John Mueller said on Twitter "last I checked ...

His CSS-only chat works by combining background-images loaded via pseudoselectors and a forever-loading index page which keeps the discussion going and the messages going between browsers.