Browser edition: files stay on your device. Up to 100 MB total and 10 minutes. First use downloads a 32 MB engine. Some formats depend on codec support. Public-link downloading is not ready on this free deployment.
Convert MP3 to M4R
Convert MP3 to M4R online for free. Real conversion, batch support, no sign-up.
How to convert MP3 to M4R
- Add your fileDrop it on the page, choose it from your device, or paste it with Ctrl+V.
- ConvertAdjust settings if you like, then press the button. You'll see live progress.
- Browser processing uses original files on your device. Public-link downloading is unavailable.
What happens to your file
MP3 files are common for music libraries, podcasts, car stereos, any device, but not every app or device opens them. M4R is ideal for custom iPhone ringtones and alert tones. Spool converts MP3 to M4R with FFmpeg — real decoding and encoding, not a renamed file extension.
Lossy → lossy. Converting between compressed formats re-encodes the audio. Pick a bitrate equal to or above the source to avoid audible loss — re-encoding a 128 kbps file at 320 kbps won't make it sound better, but it won't make it worse either.
Ringtones are limited to 40 seconds; set where it starts and how long it lasts below.
iPhone ringtones must be under 40 seconds. Use our Ringtone Maker if you want to pick the exact part of the song; this page takes the first 30 seconds by default. After downloading, drag the .m4r into Finder (macOS) or iTunes (Windows) with your iPhone connected, or use GarageBand on the iPhone to set it.
Settings
- Start at
- Length (max 40 s)
MP3 vs M4R
| MP3 | M4R | |
|---|---|---|
| Full name | MPEG-1 Audio Layer III | iPhone Ringtone |
| Created by | Fraunhofer IIS / MPEG, 1993 | Apple, 2007 |
| Type | Lossy audio | Lossy audio |
| Typical contents | MP3 (lossy) | AAC (lossy), up to 40 seconds |
| Best for | music libraries, podcasts, car stereos, any device | custom iPhone ringtones and alert tones |
| Strength | Universal compatibility | The only ringtone format iPhones accept |
| Weakness | Lossy: some detail is discarded | Maximum length of 40 seconds |
About MP3
- Type
- MPEG-1 Audio Layer III
- Contains
- MP3 (lossy)
- Use
- music libraries, podcasts, car stereos, any device
About M4R
- Type
- iPhone Ringtone
- Contains
- AAC (lossy), up to 40 seconds
- Use
- custom iPhone ringtones and alert tones
FAQ
What bitrate should I choose for M4R?
192 kbps is a good default for music. Choose 320 kbps for the best quality, 128 kbps for podcasts and voice, 64 kbps for small voice notes.
Can I convert several MP3 files at once?
Yes. Drop up to 10 files at a time — each one is converted in parallel and you can download them individually or all at once.
Is there a file size limit?
Convert and edit files on your device. The browser edition accepts up to 100 MB total, media up to 10 minutes and video up to 4K. Codec availability and device memory can limit individual jobs.
Is this MP3 to M4R converter free and safe?
Yes. There are no pop-ups, redirects or fake download buttons, and no software to install. Files are transferred over HTTPS, processed in isolated job folders and deleted automatically.