Converting Opus to FLAC gives you a larger file with identical content. It runs in your browser: nothing is uploaded, there is no queue and no size limit.
What changes when you convert Opus to FLAC
- FLAC is lossless, but it cannot restore what Opus already threw away. The file will be larger, often much larger, with exactly the same picture in it.
When to convert, and when not to
Convert to FLAC for archiving music losslessly. Lossless compression, about half the size of WAV.
Keep Opus for voice, podcasts, low-bandwidth streaming. The best quality per kilobyte, especially for speech. What WhatsApp and Discord use.
Do not convert to FLAC hoping to improve quality: the detail Opus discarded is gone. Convert only when a tool insists on FLAC.
How to convert Opus to FLAC
- Drop your Opus file on the converter above, or click to choose. Several at once is fine.
- Check the options if you need them: there are none for this pair, it just works.
- Click Convert, then Download. Nothing was sent anywhere, your browser did the work.
Questions
Is my Opus file uploaded?
No. The conversion runs in your browser with WebAssembly. There is no upload endpoint on this site. You can open your browser's Network tab, or go offline after the page loads, and it still works.
Is there a file size limit?
No fixed one. The limit is your device's memory: a large audio file on a phone is slower than on a laptop, but nothing is rejected for being big.
Is it free?
Yes, without an account, without a daily cap and without a watermark. Your device does the computing, so there is no server bill to pass on.
Will the quality drop?
No. FLAC is lossless: the audio content is stored exactly.
Can I convert several files at once?
Yes. Drop them all; each is converted in turn and you can download them one by one or as a single ZIP.
Which engine does the conversion?
Media engine (FFmpeg, multithreaded WebAssembly), compiled to WebAssembly and running in your browser, on all your CPU cores when the browser allows it. First use downloads about 31 MB, cached afterwards.