1. Home
  2. Audio Converter
  3. Convert OPUS to AU

What is OPUS?

Opus is a modern, open-source audio codec designed for interactive speech and music transmission over the internet.

What is AU?

Sun AU is the native audio format for Sun Microsystems workstations, using simple mu-law encoding or uncompressed PCM.

When Should You Use OPUS vs AU?

Use OPUS When...

Reach for OPUS when your priority is voip, streaming, gaming communication — its efficient compression makes sharing fast and storage minimal.

Use AU When...

Reach for AU when your priority is legacy unix audio, sun workstation sound — its uncompromising quality ensures every detail is preserved.

OPUS vs AU: Key Differences

  • •The core technical difference: OPUS relies on lossy compression whereas AU uses lossless compression.
  • •Converting from OPUS to AU changes compression type: lossless source becomes larger but with full quality preservation.
  • •Transparency: N/A
  • •Storage footprint: Smallest among quality codecs at same bitrate for OPUS vs Small to medium, similar to WAV for AU.
  • •OPUS is optimized for voip, streaming, gaming communication while AU is designed for legacy unix audio, sun workstation sound — choose based on your specific workflow needs

Advantages of OPUS

  • ✓OPUS compresses data using lossy methods, keeping file sizes manageable for VoIP, streaming, gaming communication.
  • ✓Industry-wide support means OPUS files open anywhere — from legacy systems to the latest devices.
  • ✓Small file sizes make OPUS ideal for email, web uploads, and cloud storage.
  • ✓From professional software to open-source alternatives, OPUS works out of the box.

Advantages of AU

  • ✓AU applies lossless compression specifically calibrated for Legacy Unix audio, Sun workstation sound.
  • ✓AU enjoys broad native support across operating systems, browsers, and creative tools alike.
  • ✓AU guarantees every bit of the original data survives — no approximations, no shortcuts.
  • ✓You will find AU support built into virtually every tool that handles Legacy Unix audio, Sun workstation sound — no plugins or converters needed.

Common Use Cases for OPUS to AU Conversion

  • Conference call recordings
  • Field recording preservation
  • Music production and mixing
  • Podcast distribution
  • Voice recordings
  • Streaming services

Industry Applications

Medical TranscriptionRadio BroadcastingMusic ProductionPodcastingBroadcastingAudio Engineering

Best Practices for OPUS to AU Conversion

  • →For OPUS to AU: match the sample rate and bit depth to your delivery platform — 44.1 kHz / 16-bit is the standard for music
  • →Apply loudness normalization (LUFS) before conversion to ensure consistent volume across your audio library
  • →AU prioritizes quality — ensure your storage can accommodate the resulting file sizes
  • →Check that metadata tags (artist, album, track number) survive the conversion
  • →Convert a short segment first to verify quality at your chosen bitrate
  • →Keep a lossless master copy in case you need to re-encode for a different platform

Related Article

Video Compression Guide: Reduce File Size Without Losing Quality

Learn more about OPUS and AU formats in our detailed guide.

Troubleshooting OPUS to AU Conversion

  • !AU audio quality degraded vs OPUS → use a higher bitrate (at least 256 kbps for music)
  • !AU file won't play on your device → check format compatibility with your player or platform
  • !Metadata (artist, album, title) lost after OPUS to AU conversion → some formats like AU may not support ID3 tags
  • !Volume changed after converting OPUS to AU → normalize audio levels before conversion for consistent playback

Related Audio Converters

Convert OPUS to Other Formats

OPUS → MP3
Convert OPUS to MP3
OPUS → MP4
Convert OPUS to MP4

All Audio Formats

View all Audio converters →

More Audio tools

Convert to AU →Convert from OPUS →

Convert OPUS to AU Online - Free & Fast

Convert OPUS files to AU online for free. High-quality conversion with no registration required.

Audio Converter

Upload or enter a URL to convert OPUS to AU instantly

Click to upload or drag & drop OPUS file

or paste from clipboard

.opus,.OPUS (max 100MB)

SSL EncryptedAuto-deleted in 1 hourProcessed securelyNo registration needed

Verifying security check…

About OPUS and AU

OPUS

OPUS (Opus audio) - Opus, modern open-source audio codec for streaming. Best for voip, streaming, gaming communication.

AU

AU (AU audio) - Sun AU, legacy Unix audio format for Sun workstations. Ideal for legacy unix audio, sun workstation sound.

Format Comparison

CompressionLossy → Lossless
TransparencySupported
Use CaseConvert from voip, streaming, gaming communication to legacy unix audio, sun workstation sound
File Size~Small to medium, similar to WAV after conversion

FAQs

Is converting OPUS to AU free?

Yes, GoConvertFile offers free conversion of OPUS to AU for files up to 100MB. No registration required.

How long does it take to convert OPUS to AU?

Most OPUS to AU conversions complete within seconds for standard-sized files. Larger files may take longer depending on the conversion complexity.

What is AU best used for?

AU is ideal for legacy unix audio, sun workstation sound. Sun AU, legacy Unix audio format for Sun workstations

Does converting OPUS to AU lose quality?

No, converting OPUS to AU does not cause additional quality loss — AU uses lossless compression. However, any artifacts already present in the original OPUS file will persist in the AU output.

What file size should I expect after converting OPUS to AU?

AU files are typically 2-5x larger than equivalent OPUS files because AU preserves all pixel data. This is expected and necessary for lossless quality.

Related Tools

MP3 to OPUS
Convert MP3 to OPUS
MP3 to AU
Convert MP3 to AU
WAV to OPUS
Convert WAV to OPUS
WAV to AU
Convert WAV to AU
View all audio converter converters
Tune output for this audio conversion
80%