What Is an M4R File?

A file with the M4R file extension is an iTunes Ringtone file. They can be created and transferred to an iPhone to use custom ringtone sounds.

These files are actually just .M4A files that have been renamed to .M4R. The file extensions are different only to differentiate their purposes.

How to Open an M4R File

Open M4R files with Apple's iTunes program. If they aren't copy protected, they can be opened using the free VLC software and other media players.

To open the ringtone with a different program, try renaming the extension to .MP3 first. Most media players recognize the MP3 format but they may not support loading files that have the .M4R extension.

How to Convert an M4R File

You're probably not looking to convert the file to another format, but instead to convert a file like an MP3 to the M4R format so that you can use it as a ringtone. Convert it with iTunes by following these steps at Switching to Mac.

What you're doing is converting an M4A or MP3 file from your iTunes library to M4R, and then re-importing the file back in to iTunes so that your iPhone can sync with it and copy over the new ringtone file.

Several free audio converter software programs convert to and from this format. FileZigZag and Zamzar save the file to formats like MP3, M4A, WAV, AAC, OGG, and WMA.

Still Can't Open the File?

Some files have a similar file extension but that doesn't necessarily mean that the formats are related and that they can be used with the same programs.

For example, M4E are used for some videos, M4Us for playlists, and M4s for Macro Processor Library text files. If you can't open your file as an audio file, double-check that you're reading the file extension correctly.

You might even have a file that just shares one of the letters, like an M file.

If you don't really have a file that ends with the M4R file extension, research the letters/numbers you see after the file's name to learn more about the format and which program you need to open/edit/convert it.