How does FullStory work?

If you’ve ever built or modified a website, then you’ve seen HTML. The tags in HTML (e.g., ) generate what are called Document Object Model elements (DOM elements, for short). The styles applied to these elements (size, colors, borders, background images, and so forth) are defined by Cascading Style Sheets, or CSS. Dynamic sites (often referred to as AJAX) work by running code in Javascript to manipulate these elements in response to user interactions. We realized that if we record all DOM elements, along with their associated CSS styles, then we can reproduce a static web page precisely. Then, if we can record all changes to the page, we can reproduce a dynamic web page just as precisely. So that’s exactly what FullStory does.