Web Page Complexity

A measure of how much a web page contains in terms of interactivity, embedded media, and structural richness. The W3C's WCAG-EM defines complexity through three factors: level of interactivity, source and method of content generation, and implementation style. Quantitative proxies include the ratio of rich HTML elements (embedded and interactive elements such as iframe, video, button, input, svg) to total DOM elements, the arrangement and density of block-level elements, and the variety of media types. Web page complexity matters for accessibility because complex pages tend to introduce more potential barriers, and because sampling strategies (e.g., OPTIMAL-EM) use complexity — and more importantly its variance within clusters of similar pages — to prioritise audit effort.