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

What is AU?

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

What is OPUS?

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

When Should You Use AU vs OPUS?

Use AU When...

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

Use OPUS When...

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

AU vs OPUS: Key Differences

  • •AU uses lossless compression while OPUS uses lossy compression — this is the fundamental technical difference between the two formats.
  • •The switch from lossless compression to lossy compression means you gain significant space savings while accepting minor quality trade-offs.
  • •Alpha channel support: OPUS lacks transparency support, so semi-transparent pixels from the source will be lost.
  • •File sizes: AU files typically range Small to medium, similar to WAV and OPUS files Smallest among quality codecs at same bitrate.
  • •AU is optimized for legacy unix audio, sun workstation sound while OPUS is designed for voip, streaming, gaming communication — choose based on your specific workflow needs

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.

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.

Common Use Cases for AU to OPUS Conversion

  • Video game audio assets
  • Film soundtracks
  • Radio commercials
  • Guided meditation recordings
  • Audiovisual installation
  • Music education

Industry Applications

Game AudioFilm Post-productionAudiobook PublishingMusic StreamingLive SoundForensic Audio

Best Practices for AU to OPUS Conversion

  • →For AU to OPUS: 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
  • →OPUS 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 AU and OPUS formats in our detailed guide.

Troubleshooting AU to OPUS Conversion

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

Related Audio Converters

All Audio Formats

View all Audio converters →

More Audio tools

Convert to OPUS →Convert from AU →

Convert AU to OPUS Online - Free & Fast

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

Audio Converter

Upload or enter a URL to convert AU to OPUS instantly

Click to upload or drag & drop AU file

or paste from clipboard

.au,.AU (max 100MB)

SSL EncryptedAuto-deleted in 1 hourProcessed securelyNo registration needed

Verifying security check…

About AU and OPUS

AU

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

OPUS

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

Format Comparison

CompressionLossless → Lossy
TransparencyN/A
Use CaseConvert from legacy unix audio, sun workstation sound to voip, streaming, gaming communication
File Size~Smallest among quality codecs at same bitrate after conversion

FAQs

Is converting AU to OPUS free?

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

How long does it take to convert AU to OPUS?

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

What is OPUS best used for?

OPUS is ideal for voip, streaming, gaming communication. Opus, modern open-source audio codec for streaming

Does converting AU to OPUS lose quality?

Yes, converting AU to OPUS uses lossy compression, which reduces file size by discarding some visual data. Set quality to 85-95% for a good balance of quality and file size.

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

OPUS files are typically 50-80% smaller than AU files because OPUS uses efficient lossy compression. The exact reduction depends on quality settings.

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%