Convert AU to AIFF
Free online AU to AIFF converter. No signup required.
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Max file size: 100 MB
Why Convert AU to AIFF?
Understand when and why this conversion makes sense for your workflow.
Converting Sun AU Audio to AIFF 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.
Sun AU Audio has a known limitation: largely obsolete for general-purpose audio use. In contrast, AIFF Audio offers a key advantage: completely lossless with full PCM audio quality. While Sun AU Audio is commonly used for unix and solaris system audio and sound effects, AIFF Audio is better suited for professional audio production on macos.
MegaConvert processes your AU file and delivers a properly encoded AIFF output, preserving audio quality within the limits of the target format — free, instant, and private.
AU vs AIFF: Format Comparison
Side-by-side comparison of the source and target formats.
| Property | AU (Source) | AIFF (Target) |
|---|---|---|
| Extension | .au | .aiff |
| Full Name | Sun AU Audio | AIFF Audio |
| Compression | Varies | Uncompressed |
| File Size | Varies | Large |
| Best For | Unix and Solaris system audio and sound effects | Professional audio production on macOS |
| Browser Support | Varies | Varies |
How to Convert AU to AIFF
Follow these simple steps to convert your file in seconds.
Upload your AU audio
Drop your .au audio file into the upload zone or browse to select it. Both short voice clips and full-length tracks work — typical Sun AU Audio files (under 100 MB) upload in seconds even on a slow connection. Album art and metadata in the file are read automatically.
Start the AIFF encode
Press the convert button to start. The audio stream is decoded from Sun AU Audio into PCM, then re-encoded as AIFF 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.
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.
Download your .aiff file
When the conversion finishes, click the download link to save the new AIFF 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 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/basicAU 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/aiffAIFF (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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