Download video and audio from youtube in one click auto convert system in your firefox browser easily. Just do these steps and got thats feature.
first go to the Add-ons on firefox:
Now search Add-ons with “youtube video downloader”:
Now install “YouTube Video and Audio Downloader” from the list below and restart your browser. Now open www.youtube.com and go any video you will see a download icon apear below of the video.