Audio
Turn your Opus files into FLAC in seconds. Everything happens in your browser: nothing is uploaded to any server.
Drag your files here
Or paste them with Ctrl+V. They never leave your device.
Some old, car or Apple players do not recognise it. As FLAC it is stored losslessly and much smaller than a WAV.
Opus is a modern, open codec that gives very good quality at a very small size, for both voice and music.
Strengths: It is the format of WhatsApp voice notes and video calls, and sounds good even at 96 kbps.
Limits: Some old, car or Apple players do not recognise it.
FLAC compresses audio without losing anything: it plays back exactly like the original.
Strengths: Ideal for archiving music at CD quality or better in about half the size of a WAV.
Limits: It weighs several times more than an MP3 and some simple devices do not play it.
No. The Opus to FLAC conversion runs entirely in your browser, with code downloaded from this site and executed on your device. You can check it in the Network tab of the developer tools or by going offline after the page loads.
No: FLAC stores audio losslessly (any loss already in the Opus cannot be recovered).
Up to 2 GB on desktop and 500 MB on mobile (less on low-memory devices), and up to 12 hours of audio on desktop. If it is over, you are told before it starts.
Yes. Drop as many Opus files as you like: several are converted at the same time, depending on your processor cores, and when they finish you can download each FLAC or all of them in a ZIP.