What is the suffix of iPhone SMS ringtone?

M4R's. You can directly use iTunes to convert. I don't recommend you to use 9 1 assistant. This method does not go through iTunes, and will not synchronize songs immediately. If you do this, add your songs to the iTunes library first, will you? Then right-click the song, there is an option to convert it to AAC format, and then select it, and then iTunes will convert the song, and the converted song will also be displayed in iTunes, as if it were stored in "My Documents" in "iTunes ..." in "My Music". Then change the extension of this file, that is, the suffix, ".m4a" to ".m4r", and then put this file back into the iTunes database, you can see it at the bell, and go in directly after synchronization. It's simple.