Convert AIFF to AU

Free online AIFF to AU converter. No signup required.

Drag & drop your file here

or click to browse

Max file size: 100 MB

Why Convert AIFF to AU?

Understand when and why this conversion makes sense for your workflow.

Converting AIFF Audio to Sun AU Audio ensures your audio files work across the widest possible range of devices, players, and streaming platforms. Audio formats differ significantly in their compression algorithms, bitrate support, and metadata handling. Whether you're archiving a music collection, preparing tracks for a podcast, or optimizing audio for a mobile app, selecting the right output format is essential for balancing playback compatibility with sound fidelity.

AIFF Audio has a known limitation: very large file sizes comparable to WAV. In contrast, Sun AU Audio offers a key advantage: simple, well-documented format with a minimal header. While AIFF Audio is commonly used for professional audio production on macos, Sun AU Audio is better suited for unix and solaris system audio and sound effects.

MegaConvert processes your AIFF file and delivers a properly encoded AU output, preserving audio quality within the limits of the target format — free, instant, and private.

AIFF vs AU: Format Comparison

Side-by-side comparison of the source and target formats.

PropertyAIFF (Source)AU (Target)
Extension.aiff.au
Full NameAIFF AudioSun AU Audio
CompressionUncompressedVaries
File SizeLargeVaries
Best ForProfessional audio production on macOSUnix and Solaris system audio and sound effects
Browser SupportVariesVaries

How to Convert AIFF to AU

Follow these simple steps to convert your file in seconds.

  1. Upload your AIFF audio

    Drop your .aiff audio file into the upload zone or browse to select it. Both short voice clips and full-length tracks work — typical AIFF Audio files (under 100 MB) upload in seconds even on a slow connection. Album art and metadata in the file are read automatically.

  2. Start the AU encode

    Press the convert button to start. The audio stream is decoded from AIFF Audio into PCM, then re-encoded as Sun AU Audio at a quality preset that matches the source bitrate where possible. Sample rate, channel count, and bit depth are preserved unless the target format restricts them.

  3. Wait for the audio to finish encoding

    Encoding speed depends on the length of the audio and the codec. Short clips finish in a few seconds; full-length albums can take 30 seconds or so. We do not throttle conversions — the limit is just the encoder's natural speed on the underlying hardware.

  4. Download your .au file

    When the conversion finishes, click the download link to save the new Sun AU Audio file to your computer. The file is yours — no watermarks, no expiration on the file itself, and no MegaConvert account is required to download it.

Tips for Converting AIFF to AU

Practical advice to get the best results from this conversion.

Why this conversion is worth doing

AIFF Audio has a known limitation: very large file sizes comparable to WAV. Sun AU Audio addresses this with a key advantage: simple, well-documented format with a minimal header. Converting from AIFF to AU is most worthwhile when this specific trade-off matters for the way you intend to use the file.

Match the format to the actual workflow

AIFF Audio is most commonly used for professional audio production on macos, while Sun AU Audio is the standard for unix and solaris system audio and sound effects. If your workflow is closer to the second pattern, converting makes sense. If you are still working in a context where AIFF is the norm, converting may create unnecessary compatibility friction with collaborators or tools that expect the source format.

Watch for this limitation in the AU output

Sun AU Audio has its own limitation worth understanding before you commit: largely obsolete for general-purpose audio use. After the conversion completes, open the AU file and verify that this limitation does not affect your specific use case — for some workflows it is irrelevant; for others it can be a deal-breaker.

Understand lossy vs. lossless before converting

Converting from a lossy format like MP3 to a lossless format like FLAC or WAV does not restore lost audio data — it only changes the container. If you need true lossless quality, always start from an uncompressed or lossless source. Converting lossless to lossy, however, is a valid way to reduce file size for streaming or mobile playback.

Understanding AIFF and AU Formats

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

Source Format

AIFF Audio

audio/aiff

AIFF (Audio Interchange File Format) is an uncompressed audio format developed by Apple, based on the IFF (Interchange File Format) structure. Like WAV, it stores raw PCM audio data at full quality, but uses big-endian byte ordering. AIFF is the standard uncompressed audio format in macOS and professional audio production on Apple platforms.

Advantages

  • Completely lossless with full PCM audio quality
  • Native support in macOS and all Apple audio software
  • Supports embedded metadata including loop points for music production

Limitations

  • Very large file sizes comparable to WAV
  • Less universal than WAV on non-Apple platforms
  • Not suitable for portable use or streaming due to file size

Common Uses

  • Professional audio production on macOS
  • Apple ecosystem audio recording and editing
  • Music production sample libraries and loop files

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 AIFF to AU.

Related Conversions

Explore other conversions related to AIFF and AU.