Usually we play YouTube on Mac online by via of web browser like Safari, Firefox or Opera. In this way, we must install Adobe Flash Player and ensure high speed of internet connection. Even so, we often fail to play YouTube on Mac: often get blank screen, choppy frames or fuzzy video.
To solve "can't play YouTube video or audio on Mac online", a recommended solution is to download YouTube to Mac as well as convert YouTube to Mac compatible format so as to play YouTube offline on Mac. Bigasoft YouTube Downloader Pro for Mac is just the right YouTube to Mac Converter and Downloader software! It can fast download as well as convert YouTube video to Mac supported video format like MP4, MOV, M4V format; it even enables to download and convert YouTube video to Mac supported audio format including MP3, M4A, AIFF, AAC and etc. Then it is just easy to: play YouTube on Mac QuickTime or iTunes, edit YouTube on Mac Final Cut Pro X/Final Cut Pro/Final Cut Express/iMovie; transfer YouTube to iPod/iPhone/iPad for playback on the go
Step by step guide at http://www.bigasoft.com/articles/youtube-to-mac-converter-download-convert-youtube-to-mac.html