Convert mp4 to opus
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 MP4 files as you like.
Real OPUS output
Encoded by ffmpeg, the same library the command-line tools use — not a renamed extension.
About MP4
MPEG-4 Part 14
An ISO container standard (ISO/IEC 14496-14) based on Apple's QuickTime format. It usually holds H.264 or H.265 video with AAC audio. Use it when a video has to play on any phone, browser, TV or editing app.
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.