M4R file format
| Extension | .m4r |
| Category | audio |
| Programs | Apple QuickTime Player |
| Main program | Apple iTunes |
| Description | M4R is a specific file format primarily used in the iPhone series for its ringtones. M4R is a variation of the AAC and M4A formats. Not all audio files from the iTunes Store are compatible with the M4R format. M4R files are automatically transferred to the iPhone when synced with a computer. Various audio formats can be converted to high-quality M4R iPhone ringtones. |
| Technical details | The M4R format adheres to the MPEG-4 standard (ISO-IEC 14495-3). Auditory masking, essentially, reduces M4R file sizes while preserving sound quality similar to AAC and MP3 files. Users can use any audio file as a ringtone or alert. |
| MIME type | audio/aac |