Systems and methods are described for server-side contextual analysis of content available at a given uniform resource identifier (URI), which utilizes headless browser techniques to analyze a more complete and accurate version of page content than using existing techniques. For example, systems and methods are described for performing contextual analysis of content that would typically be displayed to a client device but is not included in an HTML file or other initial page source file available at the initially provided URI. The contextual analysis performed may include analyzing text using natural language processing and analyzing images using computer vision techniques.