One advantage of Flash over HTML5 video (in Firefox, at least) is that Flash has its own H.264 decoder for platforms that don&#x27;t include one (like Windows XP or the &quot;N&#x2F;KN editions&quot; of Windows for Europe and Korea). Flash can also use the GPU for decoding or compositing of video on XP, providing better performance than Firefox playing VP9 using a software decoder.<p>YouTube recently relegated Flash to the bottom of its list of preferred video formats. Firefox users on XP who used to get hardware-accelerated 1080p video using Flash now get VP9. Many older XP machines can&#x27;t keep up decoding VP9 in software. I recommend Firefox users on XP install the &quot;YouTube Flash Video Player&quot; add-on, which will force YouTube to use Flash again:<p><a href="https:&#x2F;&#x2F;addons.mozilla.org&#x2F;en-US&#x2F;firefox&#x2F;addon&#x2F;youtube-flash-video-player&#x2F;" rel="nofollow">https:&#x2F;&#x2F;addons.mozilla.org&#x2F;en-US&#x2F;firefox&#x2F;addon&#x2F;youtube-flash...</a>