There are many web browser plugins available for downloading Youtube videos but its very likely that you already have a lot of other extra tools on your web browsers, so this option is pretty convenient to use.

Keepvid.com is a website that lets you download the Youtube videos.

Enter Video URL

Simply copy the video link from Youtube and paste it on Keepvid.com URL field on its front page and click the Download button.

If its your first time then it will ask you to download Java because it needs java applets to give you download links. Allow your web browser to download the required Java plugin, its safe.

Then it will display you the list of all available video formats.

Video Download Options on Keepvid

If you need a high quality video then select the MP4 format at the bottom.