Convert to Opus
Files never leave your device.
About Opus
Opus is a modern lossy codec that sounds good at very low bitrates — WhatsApp voice notes, Discord and YouTube use it. Convert to Opus for the smallest files that still sound good, especially for voice. Drop in any audio or video file — the audio is converted in your browser, and nothing is uploaded.
Questions
Are my files uploaded?
No. The conversion runs in your browser, on your device. Your files are never sent to a server, and closing the tab discards everything.
Will converting to Opus lose quality?
Opus is a lossy format, so a little detail is traded for a much smaller file. We use 160 kbps by default, or the source’s own bitrate when it’s lower, so the file is never bigger than it needs to be. You can change the bitrate, sample rate and channels in the settings.
Is there a file size limit?
There’s no set limit. Files are converted on your device, so very large ones depend on its free memory and storage — an hour-long recording converts fine on a recent phone.
Can I convert several files at once?
Yes. Add as many files as you like; they convert one after another to Opus, and you can download each one or all of them together.
Which browsers does it work in?
Current Chrome, Edge, Firefox and Safari on desktop, and Chrome and Safari on phones. Firefox on Android can’t create Opus files. If a file can’t be converted in your browser, its row says so.