Captions Search lets you search for keywords within the closed captions for videos of TV shows on the site. Closed Captioning is the transcript and text from a television or video screen that’s often used as a way for the hearing-impaired to watch television.
The new feature also lets you see a quick preview of a search results, by hovering your mouse over the thumbnail with the segment of the video that includes the search term included. One of the compelling parts of Captions Search is the linear heat map that shows what users are interested in when watching a video. So you can use the graph to jump to a set of captions (kind of like a timeline), and then you do a search for captions in a given video, Hulu will show which parts of the video (via blue bars) where there are matching results. You can also use the heat map to find popular segments within a video. Hulu says that it analyzes several search terms to generate the visual graph.