When your favorite audio content is available in the MP4 format over the web, you can download the file and then do the conversion. There are many situations when you would need to convert MP4 files to WAV format. Then it comes to the need to convert MP4 to WAV online. But, if your requirement is the soundtrack or the audio file, then having them in an audio format like WAV is the best choice. MP4 is a container format, and thus apt for playing media with multiple content types. When it comes to playing media on different types of devices or over the web, MP4 is the most commonly and popularly used format.