How can I keep the sound of a video along with the video?

[boostbysocial]

If you are interested in retaining both video and sound, you should consider a converter that can convert a youtube to mp4 file, rather than one that will merely convert an audio file to an MP4. MP4 is the most widely used and will play on virtually any device without additional software. Boostbysocial provides this as one of its formats, so you can choose a video rather than an audio in a couple clicks. It is useful when you want to view a video offline again—such as a tutorial video or a recorded call. Remember, video files are larger than audio files.