AU file (AU) stores data in the AU format. Advanced Audio Coding (AAC) uses psychoacoustic lossy compression similar to MP3 but with improved efficiency, delivering better quality at the same bitrate. This conversion changes the file's encoding, compression method, and supported feature set. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. The result is a standard AAC file readable by any compatible application. 1converter handles AU-to-AAC conversion server-side: files are uploaded over HTTPS, processed on isolated cloud infrastructure, and the converted output is available for download for 24 hours before automatic deletion. No account is required for standard conversions.