Advanced Audio Coding (AAC) uses psychoacoustic lossy compression similar to MP3 but with improved efficiency, delivering better quality at the same bitrate. MPEG-4 Part 14 Video (MP4) packages H.264 or H.265 video with AAC audio in a container format widely supported across every platform and device. This wraps the audio track in a video container, which some platforms require for upload. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. The result is a standard MP4 file readable by any compatible application. 1converter handles AAC-to-MP4 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.