[header] How to download youtube videos on mac os x [title] Navigate to the youtube video you want downloaded to your mac. [title] Click in the address bar of your browser, and press command + c to copy the url. [title] Navigate to the keepvid website at keepvid.com. 
[step] This site allows you to download youtube videos without using third-party software. [title] Click in the " download " field at the top of the site, and press command + v to paste the url.