Jul 12, · Step 2. Set Output Format as 3GP. On the main window, select Converter, and click on Add Files to import the downloaded video. Open the Output Format menu by clicking on the “Output Format” button on the right after downloading the videos. slicelive.com is a perfect online video download service, you can easily download your favorite video, audio, movies and musics from youtube using it without any restrictions. As an online youtube downloader, you can Conveniently download high quality video and audio files from youtube in mp4, 3gb, mp3 format etc. There now exists more than a couple of software programs designed to enable users to download YouTube videos from the web. If you would like to enjoy the lovely YouTube on your phone, you’d better make the YouTube in 3GP.