Convert opus to aac
Converted on your device. Files never leave this tab. Output tops out around 2 GB.
Nothing is uploaded
The converter runs inside this page. Cut your network after it loads and it still works.
No account, no daily limit
No sign-up, no daily limit, no watermark, no queue behind other people's files. Batch as many OPUS files as you like.
Real AAC output
Encoded by ffmpeg, the same library the command-line tools use — not a renamed extension.
About OPUS
Opus
An open, royalty-free lossy codec standardized by the IETF as RFC 6716 in 2012, built for speech and music at low bitrates. WebRTC calls and WhatsApp voice notes use it, usually inside an Ogg container. Use it for the smallest files at good quality for voice, podcasts or music, when the player supports it.
About AAC
Advanced Audio Coding
The lossy codec standardized in MPEG-2 and MPEG-4 as a successor to MP3, generally sounding better at the same bitrate. A .aac file is a bare ADTS stream without the MPEG-4 container an M4A has. Use it for players and streaming tools that want a raw AAC stream; for a music library, M4A holds the same audio with better tagging.