 The Document Picture-in-Picture API makes it possible to open an always-on-top window that can be populated with arbitrary HTML content. The Picture-in-Picture window in the Document Picture-in-Picture API is similar to a blank, same-origin window open via window.open with some differences. First, the Picture-in-Picture window floats on top of other windows. The Picture-in-Picture window never outlives the opening window. The Picture-in-Picture window cannot be navigated, and the Picture-in-Picture window position cannot be set by the website.