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Why convert MP4 to AU?
Fast
Your file is converted in under 30 seconds in our cloud.
Secure
Files are automatically deleted after 1 hour.
Quality preserved
Maximum quality preserved during conversion.
About the MP4 format
MP4 — MPEG-4 Part 14
MP4 is the world's most widely used video format, adopted universally across devices, streaming platforms, and video editing software. Based on the MPEG-4 standard, it delivers excellent video quality at relatively small file sizes.
Common uses
- Online video streaming (YouTube, Netflix)
- Social media videos
- Smartphone video recording
- Digital downloads and purchases
About the AU format
AU — Sun Microsystems Audio Format
AU is a simple audio format developed by Sun Microsystems and used in Unix/Linux environments. It supports multiple audio encodings and was commonly used in Java applications and Unix systems.
Common uses
- Legacy Unix/Linux audio files
- Java audio applications
- System sounds
- Old internet audio clips
Related conversions
Other conversions available for MP4 and AU files
Frequently asked questions
How do I convert MP4 to AU?
Upload your MP4 file above, choose AU as the output format, then click Convert. Your AU file is ready to download in seconds — nothing to install, and it works in your browser.
Is the conversion free?
Yes, basic conversion is completely free. For large volumes, check out our paid plans.
What is the maximum file size?
Free accounts can convert files up to 25 MB. Pro accounts up to 100 MB.
How long are my files kept?
Files are automatically deleted after 1 hour on the free plan, 24 hours on Pro.
What formats are supported?
We support over 200 source and target formats. See our complete formats page.
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