When it comes to combining audios files on Mac online, many of you should have heard of Clideo Audio Joiner. As a completely online audio merging tool, Clideo does not need you to download and install it on your Mac, which will gain time for you. Also, it is compatible with a variety of audio formats and quite simple to operate with an intuitive interface. By the way, it offers an additional function to apply a crossfade effect to audio files.