MMegaConvert

Convert MP3 to AU

Free online MP3 to AU converter. No signup required.

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Max file size: 100 MB

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How to Convert MP3 to AU

Follow these simple steps to convert your file in seconds.

  1. 1

    Upload your .mp3 file

    Drag and drop your .mp3 file into the upload area, or click "Browse" to select it from your device. Your file is uploaded securely and processed on our servers.

  2. 2

    Click "Convert to AU"

    Once your file is uploaded, press the convert button to start the MP3 to AU conversion process.

  3. 3

    Wait for the conversion to complete

    The conversion usually takes just a few seconds. You can see the progress in real time while your file is being processed.

  4. 4

    Download your converted .au file

    When the conversion is finished, click the download button to save your new .au file. The file is ready to use immediately.

Understanding MP3 and AU Formats

Learn about the source and target file formats to understand what happens during conversion.

Source Format

MP3 Audio

audio/mpeg

MP3 (MPEG-1 Audio Layer III) is the most widely used lossy audio compression format, developed by the Fraunhofer Society and standardized in 1993. It achieves significant file size reduction by using psychoacoustic modeling to discard audio frequencies less perceptible to human hearing. MP3 typically compresses audio to about one-tenth of its original size while maintaining acceptable quality for most listeners.

Advantages

  • Universal compatibility across virtually all devices, players, and platforms
  • Excellent compression with adjustable bitrate from 32 to 320 kbps
  • Massive existing library of content and widespread industry adoption

Limitations

  • Lossy compression permanently discards audio data
  • Noticeable quality degradation at lower bitrates, especially for music
  • Does not support surround sound or multi-channel audio

Common Uses

  • Music distribution and streaming
  • Podcast and audiobook distribution
  • Portable audio player and smartphone playback

Target Format

Sun AU Audio

audio/basic

AU is an audio file format introduced by Sun Microsystems and commonly associated with Unix and NeXT systems. It supports various encodings including uncompressed PCM, mu-law, and A-law compression, with a simple header structure. AU was one of the earliest audio formats supported on the web and remains used in Unix-based audio programming.

Advantages

  • Simple, well-documented format with a minimal header
  • Native support in Unix, Solaris, and Java audio APIs
  • Supports multiple encoding types including mu-law for telephony

Limitations

  • Largely obsolete for general-purpose audio use
  • Limited metadata support and no modern compression options
  • Poor support in consumer audio software and devices

Common Uses

  • Unix and Solaris system audio and sound effects
  • Java application audio playback (javax.sound)
  • Legacy telephony and voice processing systems

Frequently Asked Questions

Common questions about converting MP3 to AU.

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