We all know that OS X Lion is shipped without a Flash Player. In support of Appleâ€™sargument against Adobeâ€™s resource-hungry technology. So there is a number of solution for this problem, you could install Google Chrome which comes with the latest version of Flash Player built in or you could download Adobe Flash Player, Or you can use this Safari extension.
FlashtoHTML5 extension is developed by Joris Vervuurt. What it does is replacing the CPU-hogging YouTube Flash Player with an HTML5 video player. Youtube had its experimental HTML5 video player for some time but this is so much easier to use and it allows you to choose maximum video resolution (360p, 720p, 1080p and 4K) and it work with Flash videos embedded on other sites.
You will still be advised to upgrade to a Flash Player after the extension automatically loads an HTML5 version of the video.
FlashtoHTML5 is available for download from, it requires a Safari 5 and it fully supports OS X Lion.
Via | 9to5Mac