Free online AU to M4R converter
Convert AU audio to M4R ringtone format for iPhone compatibility.
Convert AU to M4R online - free
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How to convert au to m4r file
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AU is a simple audio file format commonly associated with Sun/NeXT systems and early Unix environments. It can store uncompressed or lightly compressed audio, but it is not widely used in modern consumer devices. M4R is an Apple ringtone format based on AAC audio in an MP4 container, designed for iPhone ringtones and alerts.
What is AU to M4R conversion?
AU to M4R conversion means taking audio stored in an AU file and saving it as an M4R ringtone file. This is useful when you want to use older audio clips, sound effects, or voice recordings as a ringtone on an iPhone.
Why convert AU to M4R?
- iPhone compatibility for custom ringtones
- Smaller file size with AAC compression
- Easy ringtone creation from existing AU audio
- Better device support compared with AU
How to convert AU to M4R
The conversion usually involves opening the AU file in an audio converter, choosing M4R as the output format, and exporting the result. Because M4R is based on AAC, the audio may need to be encoded to a compatible bitrate and trimmed to a ringtone-length clip if required by your device or workflow.
Best software for AU to M4R conversion
Audacity is one of the best free options for this task. It can open AU files and export audio through supported formats with the help of additional export options or external encoding tools. For a more direct conversion workflow, Any Audio Converter and Freemake Audio Converter are also popular choices for creating ringtone-ready files.
If you want a simple command-line solution, FFmpeg is a powerful converter. It can read AU files and encode them to AAC-based M4R output efficiently.
Recommended conversion steps
- Open the AU file in your chosen converter.
- Trim the audio if you want only a ringtone segment.
- Select M4R as the output format.
- Set AAC audio settings if available.
- Export the file and transfer it to your iPhone.
Useful software menu path
In Audacity, the typical workflow is File → Open to load the AU file, then File → Export to save it in a compatible audio format before renaming or converting to M4R if needed.
Important notes
- M4R files are usually short because they are meant for ringtones.
- Not every converter supports M4R directly, so AAC export may be required.
- AU audio quality depends on the source; conversion cannot improve poor input quality.
- iTunes or Finder may be needed to sync the ringtone to an iPhone.
Note: This au to m4r conversion record is incomplete, must be verified, and may contain inaccuracies. Please vote below whether you found this information helpful or not.
AU vs M4R: format comparison
How the AU and M4R formats compare on the properties that matter most for this conversion.
| Property | .AU Sun/NeXT audio file | .M4R MPEG-4 Ringtone File |
|---|---|---|
| Compression | Uncompressed | Lossy |
| Audio quality | — | Medium |
| Audio channels | — | Up to stereo |
| Metadata support | Basic | Basic |
| Streaming | Yes | No |
| DRM protection | No DRM | No DRM |
| Opens in a web browser | Partial | No |
| Typical file size | Large | Small |
| Open standard | Yes | Partly open |
| Best used for | Speech and voice | Music |
| Introduced | 1988 | 2007 |
| Developer | Sun Microsystems / NeXT | Apple Inc. |
| MIME type | audio/basic | — |
Frequently asked questions
Is the AU to M4R converter free?
Yes, converting AU to M4R on 101convert.com is completely free. No registration, email address or installation is required.
How large can my AU file be?
You can upload AU files up to 1000 MB and convert up to 100 files at once in a single batch.
What happens to my uploaded files?
Files are processed automatically and deleted from our servers within a few minutes after conversion. We never view or share your files.
Do I need to install any software to convert AU to M4R?
No. The AU to M4R conversion runs entirely online in your browser and works on Windows, Mac, Linux, Android and iPhone.
Did the conversion fail?
In most cases, the cause is an incorrect file format. Please upload a valid AU file for this AU to M4R conversion. Occasionally, the issue may be on our side. We analyze recurring conversion failures and disable or fix the converter if we detect a defect.