Convert GSM to M4R
Convert your GSM files to M4R online
GSM digital audio format
Developed in Europe, this format was designed for mobile users. GSM is used for audio files that contain a large amount of audio information. Suitable for voice recordings, including recordings of phone calls. You can compress and archive a GSM file to achieve a different file size. The format is mostly used to create and store voice information. There are 4 types of this format that can be opened using different applications.
M4R: the ringtone file used in Apple iOS
The M4R format is used in Apples mobile devices, mostly for storing ringtones. You can create an M4R file by converting other formats or downloading it from the official iTunes store. The sound conversion employs a special type of compression, which significantly reduces the file size. The advantages of this format make it ideal for iPhone owners. M4R is one of the constituents of the standardized MPEG-4 format. One of its strong points is that the high sound quality is fully preserved after compression.