How to Go Fullscreen on YouTube (F)

Pressing F while the video player has keyboard focus toggles fullscreen mode, expanding the player to fill the entire browser viewport and, in most browsers, the whole physical screen — hiding the browser's own tabs, address bar, and bookmarks bar entirely for a fully distraction-free viewing experience with nothing else visible. **What actually happens on screen**: the browser hands over the entire display to the video content, and depending on your specific browser and operating system, this may also hide your taskbar or dock, giving you genuinely nothing on screen except the video itself and its own on-screen playback controls, which typically fade away after a few seconds of inactivity and reappear when you move your mouse. **How this differs from theater mode**: fullscreen hides everything except the video; theater mode (T, covered in its own action page) instead widens the player within the normal page while keeping the browser's own interface and the page's title, description, and comments section still visible and scrollable below it. Fullscreen is the choice for zero-distraction, maximum-immersion viewing; theater mode is the choice when you still want quick access to the surrounding page content while watching at a larger-than-default size. **Exiting fullscreen**: pressing F again toggles back to whatever layout you were in before (either YouTube's default narrow player or theater mode, depending on which state you entered fullscreen from). The Escape key also reliably exits fullscreen in virtually every browser, functioning as a universal fullscreen-exit shortcut across the web generally, not just specific to YouTube. **Fullscreen and playback controls**: all of the seeking, speed, and caption shortcuts covered elsewhere on this site continue to work identically while in fullscreen — fullscreen changes only how much of the screen the player occupies, not which keyboard shortcuts are available or how they behave, since the same underlying player and its keyboard event handling remain active regardless of viewing mode. **A specific gotcha with fullscreen and mouse movement**: because the on-screen playback controls (progress bar, volume, settings gear) fade away automatically after a few seconds without mouse movement in fullscreen mode, and clicking directly on the video area itself toggles play/pause via mouse rather than keyboard, it's easy to accidentally pause a video by clicking to try to bring the controls back — using K (rather than clicking) to check or toggle play state avoids this specific accidental-pause pattern. **Browser-level fullscreen versus OS-level fullscreen**: most modern browsers implement YouTube's fullscreen request using the browser's native Fullscreen API, which genuinely takes over the whole physical screen rather than just maximizing the browser window — worth knowing as distinct from simply maximizing a browser window (which still shows the browser's own tabs and address bar), since fullscreen via this shortcut goes a meaningful step further than window maximization alone. **Multi-monitor behavior**: on a multi-monitor setup, fullscreen typically applies to whichever monitor the browser window was on when you triggered it, filling that specific display entirely while your other monitor(s) continue showing whatever else was open on them, rather than fullscreen spanning across multiple displays simultaneously. **Mistake to avoid**: expecting F to also increase video resolution or quality automatically is a common misconception — fullscreen only changes how large the player displays on screen, not the actual streamed video quality, which remains governed separately by YouTube's own quality settings (automatic or manually selected) in the settings gear menu, regardless of whether you're viewing in fullscreen or the default smaller player size.