If you want to convert your file into any format, Zamzar is a web-based file conversion tool that can convert your video, audio, images, and documents from nearly any format. No sign up and no download is required for converting files.
For converting a file, select file from your computer, Zamzar ask you which format to convert. You supply your e-mail address and click “convert” and Zamzar will e-mail you a link to the converted file. You can convert youtube video directly from site you just give video URL in the place of “select file”
Zamzar convert files up to 100MB for free if you want more convert, they provide basic, pro and business services.