An HTML5 animated ad is a digital display ad built with standard web technologies — HTML, CSS, and JavaScript — rather than a single static image. Instead of one flat graphic, it can move: text can slide or fade in, images and logos can animate, backgrounds can shift, and elements can transition between multiple “frames” or scenes to tell a short visual story or highlight several messages in sequence. Because it’s built from lightweight web code, it loads quickly, stays sharp on any screen size or resolution (including high-density mobile and retina displays), and remains fully clickable through to the advertiser’s landing page. HTML5 replaced the old Flash-based animated ads, which modern browsers and devices no longer support, making it today’s standard format for rich, eye-catching creative like animated mastheads, leaderboards, and rich-media units served through ad platforms such as Google Ad Manager.