Note: For information on how to create ringtones for your iPhone see this article.
To create a custom ringtone:
- Create or open an existing GarageBand song.
- Use the cycle mode to choose which portion of your GarageBand song you'd like to use for your ringtone.
Note: Ringtones are usually 30-40 seconds in length. Consult your mobile phone's documentation for guidelines on how long ringtones should be.

- Choose GarageBand > Preferences... and click Advanced. Select the checkbox labeled Auto Normalize: and set Audio Resolution: to "Better."

- Choose Share > Export Song to Disk... to open the Export window.

- Confirm the Compress checkbox is selected.
- Set Compress Using: to either MP3 Encoder or AAC Encoder. Consult your mobile phone's documentation for guidelines on its preferred audio format.
- Set Audio Settings to "Custom" to open the Encoder settings window.

- Set Bit Rate: to the bit rate recommended in your mobile phone's documentation.
- Set Channels: to Stereo or Mono, as recommended by your mobile phone's documentation.
- In the Export window, click the Export button.
- In the Export to Disk window, choose a name and location to save your ringtone.
- Follow the instructions provided in your mobile phone's documentation to copy your ringtone to the phone.
Note: This may require a Bluetooth or USB connection between your Mac and the phone. It also may require software provided by the manufacturer of the phone or a third-party.