How to convert MP3 to M4R
- Open an MP3 (M4A, WAV, Ogg and FLAC work too).
- Drag the window on the waveform, or select Find the loudest part.
- Set Length, Fade in and Fade out, and play the clip to check it.
- Keep Phone on iPhone (M4R) and select Make ringtone, then download the .m4r file.
Worked example
With the starting settings, a 30-second window with a 1-second fade in and a 2-second fade out is encoded as AAC at 192 kb/s; at that bitrate 30 seconds of audio is about 720 KB.
Formats and limits
| Input | MP3, M4A, WAV, Ogg, FLAC |
|---|---|
| Output | M4R |
| Limits | Ringtones up to 40 seconds (iPhone limit). |
| Engine | In-memory trimming with S-curve fades; AAC (WebCodecs), MP3 (LAME WebAssembly), Opus or WAV encoding via Mediabunny |
Limitations
- At most 40 seconds.
- M4R needs the browser's AAC encoder (WebCodecs); where it is missing the page says so.
- Copy-protected songs cannot be opened.
Questions
How long can an iPhone ringtone be?
Up to 40 seconds, the iPhone limit and the longest length this tool allows. It starts at 30 seconds.
Can I convert the whole song to M4R?
No. Ringtones are limited to 40 seconds, so the tool exports the part you select. For a full-length AAC file, use the audio converter and choose M4A.
Is an M4R file different from an M4A?
The sound inside is the same kind, AAC in an MP4 container. The .m4r extension is what marks the file as a ringtone for the iPhone.
Privacy
Runs on your device. Files and text are processed in this browser tab and are not uploaded.
This page opens the Ringtone maker ready for this task. See the privacy policy for how toolsdocks handles data.