OPUS to AU Audio conversion is the process of transcoding audio data from the OPUS codec/container into the AU (Sun/NeXT AU) audio format. It repackages or re-encodes OPUS-encoded audio into an AU file that uses standard PCM or other supported encodings so the audio can be played by legacy or specific audio tools that expect AU files.
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Read guide →Drag your .OPUS file from your computer or use the browse function.
Confirm .au as the selected destination format.
Click "Convert" and download your converted .AU file once ready.
The OPUS format uses the MIME type audio/opus and supports variable bitrate audio optimized for voice and music streaming. AU files use the MIME type audio/basic or audio/au, typically storing uncompressed PCM audio data. OPUS employs the Opus codec, while AU files usually contain PCM or mu-law encoded audio.
The AU Audio (.AU) format is commonly used for audio. Understanding its characteristics can be helpful when converting to or from other formats like OPUS.
While specific technical details aren't available here, AU Audio files generally serve the purpose of storing audio effectively within their domain.
Convert your OPUS audio files to AU format instantly with our reliable online converter. No downloads or complicated software needed—simply upload your OPUS file and get a high-quality AU audio file in seconds. Perfect for audio editing, compatibility, and archiving.
OPUS is a modern, highly compressed audio format optimized for streaming and low latency, whereas AU is an older, uncompressed format commonly used in professional audio environments. While OPUS offers smaller file sizes, AU provides better compatibility with traditional audio software and equipment.
Keep individual OPUS files under 250 MB for free web conversions; larger files may need desktop tools or premium services.
To preserve quality, convert OPUS to AU using a PCM output at the original sample rate and a bit depth of 16-bit or higher; avoid downsampling during conversion.
For voice recordings, using 16 kHz–22.05 kHz with 16-bit PCM balances quality and file size; for music, choose 44.1 kHz or 48 kHz and 24-bit if possible.
Use batch conversion for multiple files to save time, but confirm consistent sample rates and channel counts across files to avoid processing errors.
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Audio Engineer
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Podcaster
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Musician
Start your free OPUS to AU conversion now.
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Up to 250MB
Be aware that OPUS is a modern lossy codec: if the source OPUS file is lossy, converting to AU (lossless PCM) will not restore original detail—AU will only preserve the current quality without further loss if you select PCM without re-encoding to another lossy codec.