Convert AU to AIFF

Free online AU to AIFF converter. No signup required.

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Max file size: 100 MB

When to convert AU to AIFF

Use this conversion when your destination needs AIFF and you have a AU source. Keep the original so you can compare the result or try another supported format.

Audio is decoded and re-encoded using format-specific defaults. Sample format and some metadata may change. Embedded cover art is omitted. A lossless destination cannot recover detail lost in the source.

AU vs AIFF: Format Comparison

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

PropertyAU (Source)AIFF (Target)
Extension.au.aiff
Full NameSun AU AudioAIFF Audio
CompressionVariesUncompressed
File SizeVariesLarge
Best ForUnix and Solaris system audio and sound effectsProfessional audio production on macOS
Browser SupportVariesVaries

How to Convert AU to AIFF

Follow these simple steps to convert your file in seconds.

  1. Choose a AU file

    Select or drop one file up to 100 MB. Its extension must match this converter. Availability is checked before transfer.

  2. Convert to AIFF

    Audio is decoded and re-encoded using format-specific defaults. Sample format and some metadata may change. Embedded cover art is omitted. A lossless destination cannot recover detail lost in the source.

  3. Download and check the result

    Use Download after conversion completes. Open the result and check its content, quality and formatting before sharing it. Download links expire one hour after upload finishes. Uploaded and converted files are removed automatically by regular cleanup. Files may become unavailable sooner when the service restarts.

Tips for Converting AU to AIFF

Practical advice to get the best results from this conversion.

Why this conversion is worth doing

Sun AU Audio has a known limitation: largely obsolete for general-purpose audio use. AIFF Audio addresses this with a key advantage: completely lossless with full PCM audio quality. Converting from AU to AIFF 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

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

Watch for this limitation in the AIFF output

AIFF Audio has its own limitation worth understanding before you commit: very large file sizes comparable to WAV. After the conversion completes, open the AIFF 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 AU and AIFF Formats

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

Source 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

Target 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

Frequently Asked Questions

Common questions about converting AU to AIFF.

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