Yes! Convert999 works on any device with a web browser — iPhone, Android, iPad, or desktop. No app installation required. Simply open the converter, upload your AU file, and download the converted OPUS file.
Will I lose quality converting AU to OPUS?
Convert999 uses high-quality conversion algorithms to minimize quality loss. For lossless formats, the conversion is exact. For lossy formats like images and audio, we use optimized settings that balance quality and file size.
Can I batch convert multiple AU files to OPUS?
Yes, Convert999 supports batch conversion. Select or drag & drop multiple AU files and convert them all to OPUS format at once. Each file is processed locally in your browser.
What is the difference between AU and OPUS?
Sun Audio (AU) and Opus Audio (OPUS) differ in compression, compatibility, and features. AU is optimized for its native use cases, while OPUS may offer different advantages. Visit our AU vs OPUS comparison page for a detailed breakdown.
Why Convert AU to OPUS?
Advantages
✓Opus Audio offers better compatibility with modern applications and workflows
✓Converting is completely free with no file size limits on Convert999
✓Your files never leave your device — 100% private and secure conversion
✓Instant conversion without waiting for server processing
Key Differences
→AU (Sun Audio) is optimized for its native use cases
→OPUS (Opus Audio) may offer different compression or feature set
→Choose based on your target platform, quality needs, and file size requirements