Convert AAC to Opus

Usually about size: Opus holds up better than AAC at low bitrates, so this can shrink a file noticeably for a given perceived quality. It is still lossy-to-lossy, so don't expect an improvement in sound.

Drop AAC file(s) to start

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What is AAC?

MP3's designated successor and the audio in most video - YouTube, streaming services, broadcast, virtually every MP4. At a given bitrate it beats MP3 audibly, especially below 128kbps, and every phone and browser decodes it.

What is Opus?

The best-sounding lossy codec at low bitrates by a comfortable margin, which is why it carries the audio in nearly every voice and video call you make. Royalty-free, equally good on speech and music, and usually wrapped in an Ogg container. It always runs at 48kHz internally.

Your files never leave your device · no magic required