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Need help?How to Convert M4R to Opus Online
- Upload your M4R: Drag
.m4rringtones onto the page or click the upload button. Batch upload is supported. - Pick the Opus bitrate: Audio Codec is Opus on this page. Under File Compression choose a Quality Preset (Highest down to Lowest), a Constant Bitrate from 8 to 384 kbps, one of ten Opus Variable Bitrate bands from 6k-24k up to 320k-510k, a Custom Bitrate in kbps, or a specific target file size.
- Channel, sample rate and trim (optional): Audio Channel offers Original, Mono or Stereo; Audio Sample Rate offers Original or 8000, 12000, 16000, 24000, 44100 or 48000 Hz. Opus is built around 48 kHz audio, and if a choice has to be adjusted to fit the bitrate, the download card shows the value used. Trim keeps a section by start time and duration.
- Convert and download: Click Convert. Files are uploaded over TLS, processed on xconvert's servers and deleted automatically after a few hours.
Why Convert M4R to Opus?
An M4R is an iPhone ringtone: AAC (AAC-LC) audio in an MPEG-4 container. Opus is the open, royalty-free codec standardised by the IETF as RFC 6716 in 2012, and it is designed to sound good at very low bitrates. That makes it a good target when the point is a tiny file rather than a ringtone.
- Small clips for messaging and the web. A 30-second tone at 48 kbps is only about 180 KB, small enough to send anywhere or embed on a page.
- Voice tones and spoken alerts. Opus handles speech especially well, so a voice ringtone or recorded alert stays clear at bitrates where other codecs struggle.
- Web audio. Current versions of Chrome, Firefox and Edge play Opus, so it suits sound effects on websites and web apps.
- App and game assets. Many frameworks accept Opus, which keeps short sound effects light.
What Opus does not do is make the tone usable everywhere. It is a second lossy encode of audio that was already AAC, so the aim is a smaller file at the same perceived quality, not a better-sounding one. Car stereos, older portable players and some phone ringtone pickers still expect MP3, AAC or Vorbis. For an Android ringtone specifically, OGG Vorbis or MP3 is the safer pick; see M4R to OGG.
M4R (AAC) vs Opus — Format Comparison
| Property | M4R | Opus |
|---|---|---|
| Codec | AAC (AAC-LC) | Opus (IETF RFC 6716) |
| Container | MPEG-4 | Ogg (.opus) |
| Licensing | AAC (licensed codec) | Open and royalty-free |
| Low-bitrate strength | Good at moderate bitrates | Designed for very low bitrates, strong on speech |
| Bitrate options here | Not applicable (source) | Ten Variable Bitrate bands, 6k-24k to 320k-510k |
| iPhone ringtone | Yes | No |
| Android ringtone | Not a format Android expects | Plays on modern Android, but OGG Vorbis or MP3 is safer |
Opus Bitrate Picking Guide
Size follows bitrate: kbps × seconds ÷ 8 = kilobytes. For a 30-second clip:
| Variable Bitrate band | 30-second file | Good for |
|---|---|---|
| 6k-24k | ~23-90 KB | Speech-only alerts, mono |
| 24k-40k | ~90-150 KB | Clear speech, simple tones |
| 48k-64k | ~180-240 KB | Music clips for chat and the web |
| 64k-96k | ~240-360 KB | Music in stereo on phone speakers |
| 96k-128k | ~360-480 KB | Music with headroom for headphones |
| 128k-160k | ~480-600 KB | Rarely audible over 96k-128k when the source is a ringtone |
The higher bands up to 320k-510k exist, but a ringtone that started as AAC rarely benefits from them: they make the file larger without restoring what the AAC encode removed.
Frequently Asked Questions
Will my Opus file play on an iPhone?
Support for Opus on Apple devices is newer and depends on the app and the iOS version, so do not rely on it. For an iPhone ringtone, keep the M4R; Opus is for the places where a small, efficient file matters.
Is Opus lossy? Will I lose quality?
Yes, Opus is lossy, and converting from AAC means a second lossy encode. Opus is efficient, so at a moderate bitrate the extra loss is hard to hear, but no bitrate restores what the AAC encode already removed.
Which bitrate should I choose for a notification or voice tone?
For speech, the 24k-40k band in mono is usually clear and very small. For music, 64k-96k in stereo is a good balance for phone speakers. Go higher only if the clip will be heard on headphones. If you are aiming for a size limit instead of a bitrate, the Specific file size option sets the target directly.
Can I use Opus as an Android ringtone?
Many current Android phones play Opus, but whether the ringtone picker lists it depends on the manufacturer. OGG Vorbis or MP3 is the reliable choice for ringtones.
What is the difference between .opus and .ogg?
Both use the Ogg container. A .opus file holds Opus audio; a .ogg file usually holds Vorbis. Some older players only understand Vorbis in Ogg.
Can I turn the Opus file back into an iPhone ringtone?
Yes. Opus to M4R encodes it to AAC in an M4R and reminds you under Trim's Duration to keep it to 30 seconds or less. Each lossy round trip costs a little quality, so keep the original M4R if you can.
Can I convert several ringtones at once?
Yes. Add all the .m4r files together and each one is converted with the same Opus settings. Every result has its own download card listing the bitrate, channels and sample rate that were used, so you can check them before you share the files.
What happens to my files?
They are uploaded over TLS (HTTPS), processed on xconvert's servers and deleted automatically after a few hours. Protected (DRM) files cannot be converted. Every other output is on the M4R converter.