How do I convert MP3 to M4R?

M4R is Apple's iPhone ringtone format — technically an ordinary AAC file in an MPEG-4 container with the extension changed from .m4a to .m4r, which is what tells iOS to treat it as a ringtone. iPhones will not use MP3 files as ringtones, so converting is mandatory: this tool encodes your MP3 to AAC and packages it with the correct extension in one step.

Length matters: iOS enforces a maximum of 40 seconds for ringtones (30 seconds is the safe convention, and text tones should stay under that). Pick the exact segment of the song you want — the hook, the chorus — and trim to it, either with the built-in trim option or with Trim MP3 beforehand.

Installing the finished M4R: connect the iPhone and drag the file onto the device in Finder (macOS Catalina and later) or iTunes (Windows), where it lands under Tones. It then appears in Settings → Sounds & Haptics → Ringtone. Alternatively, the GarageBand-on-iOS route can import it without a computer.

Reasons to convert MP3 to M4R usually come down to compatibility, file-size, or specific feature requirements. Common situations:

• An app or platform only accepts M4R uploads.
• You need a feature unique to M4R (e.g. lossless editing, chapter markers, smaller streaming size, etc.) that MP3 doesn't provide.
• You're optimising file size — modern formats often produce smaller files than the older format you started with.
• You need a single archival format across a project so files behave consistently in the same viewer.

1. Open the MP3 → M4R tool on mp3.now.
2. Drag your MP3 file onto the drop zone, or click Select files. You can drop a whole folder of files at once.
3. The output is fixed to M4R. If the format supports extra options (bitrate, sample rate, channels, volume normalization), tweak them in the options panel.
4. Click Convert. The job runs on our server and finishes in a few seconds for typical tracks.
5. Download the result. Files stay in storage for 24 hours and are then permanently deleted.

The entire flow is free for the first 10 jobs per day with no signup required. A free account doubles that quota; a premium plan removes the limit entirely.

• Keep it at or under 30 seconds — iOS caps ringtones at 40 seconds, and 30 is the safe standard.
• Trim to the hook or chorus before converting; a ringtone needs to be recognisable in 2 seconds.
• Install via Finder (macOS) or iTunes (Windows): drag the .m4r onto the connected iPhone.
• If the tone doesn't appear, check the length — over-limit files are silently rejected by iOS.
• Choose a loud, dense section; quiet intros vanish in a pocket.