.M4R File Extension
File TypeiPhone Ringtone File
File format categories include Binary, Text, XML, and Zip. The format of this file type has not been determined.
What is an M4R file?
Custom iPhone ringtone created with iTunes; can only be created from songs purchased from the iTunes music store that allow ringtone creation; automatically transferred to the iPhone when the phone is synced with the computer using Apple iTunes.
NOTE: M4R files created with third-party software programs or downloaded from the Internet may not include copy protection. These files may be played by other programs such as VLC media player.