Opus is an open, royalty-free audio codec that provides high-quality compression for both speech and general audio. It is suitable for various applications, including voice over IP (VoIP) and streaming.
Common Uses
Voice calls
Low-latency streaming
Web audio
Opus Transformation FAQ
What is a Opus audio file?
+
Opus is a lossy audio format. The encoder discards inaudible frequencies and masked sounds to reach file sizes roughly a tenth of an uncompressed equivalent. Re-encoding Opus to another lossy format causes generational quality loss; convert from a lossless master when possible.
Is Opus lossy or lossless?
+
Opus is lossy — the encoder removes data the encoder judges to be inaudible to reach a small file size.
What should I convert Opus to for sharing?
+
For email and social-media sharing, convert Opus to MP3 — universal playback and small file size. For high-fidelity sharing with audiophiles, convert to FLAC or WAV to preserve the original quality.
How much will conversion change the file size?
+
Converting Opus to a lossless format like WAV or FLAC keeps the size large; converting to MP3 or AAC at common bitrates (192-320 kbps) shrinks the file by roughly 5-10x with minimal perceptible quality change.
Will my Opus ringtone work on iPhone?
+
iPhone ringtones need to be in M4R format (Apple's ringtone container). Convert Opus to M4R using MOV.to, then transfer the M4R file to your device through Finder or Apple Devices.
How long can a Opus file be before MOV.to refuses it?
+
There is no hard time limit — the cap is on file size. Free users get 100 MB per upload (often an hour or more of Opus audio at common bitrates). Pro users go up to multiple GB.
Does MOV.to preserve metadata (tags, album art) from Opus?
+
Yes — ID3 tags, artist/album/title, and embedded artwork in your Opus file are preserved in the output where the destination format supports them. WAV strips most metadata by design, so converting to WAV will drop tags.
Can I extract audio from a video as Opus?
+
Yes. Upload an MP4, MOV, MKV or any supported video and pick Opus as the output. MOV.to demuxes the audio track and re-encodes only if needed.
Does MOV.to delete my Opus files after conversion?
+
Yes. Your Opus upload and the converted output are deleted automatically after a short window. We do not retain, listen to, or share your audio.
What bitrate should I pick when converting from Opus?
+
For music, 256-320 kbps is the sweet spot — transparent to most listeners. For voice and podcasts, 96-128 kbps is plenty. Going higher than the source bitrate cannot recover quality the source already lost.