FLAC to Opus converter
Convert a FLAC into an Opus right here on the page. Opus is the usual choice for voice and video calls, WebRTC and game chat. The usual reason to do it is size, because Opus is far smaller for this sort of thing. Your file never leaves your computer.
Need the other direction? Convert Opus to FLAC
How to convert FLAC to Opus
- 1 Drop your FLAC .flac file onto the page, or click to browse for it.
- 2 Set the quality, or leave the default, which keeps the file small without anything showing.
- 3 Convert. The work happens on your own machine, so how long it takes depends on your computer and the file.
- 4 Download the Opus, or add more files and do the whole set in one go.
Why convert FLAC to Opus
- Opus files come out much smaller, which is the difference between a page that loads straight away and one that keeps people waiting.
- The best sound for the size of any widely supported format.
- Latency as low as 5 ms, suitable for real time.
- Voice and video calls, WebRTC and game chat.
- FLAC: much larger than MP3, AAC or Opus.
FLAC compared with Opus
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | FLAC | Opus |
|---|---|---|
| File extension | .flac | .opus |
| Compression | Lossless | Lossy |
| Typical file size | Larger | Smaller |
| Introduced | 2001 | 2012 |
| Developed by | Xiph.Org Foundation | Xiph.Org and IETF |
Quality and what changes
This is the step where information is discarded, and it cannot be undone by converting back later. Opus throws away detail the eye is least likely to notice, which is invisible at sensible settings and shows as blocking around sharp edges and text when pushed hard. Keep the FLAC as your master and treat the Opus as a delivery copy.
- One Opus limitation to keep in mind: car stereos and standalone players mostly will not open it.
Questions about FLAC to Opus
Is my FLAC file uploaded anywhere?
No. The whole thing runs inside the browser tab you already have open. Your FLAC is read straight from your own disk, converted on your machine and handed back as an Opus. Nothing is sent anywhere, nothing is stored and there is no account.
Is there a file size limit?
There is no server-side limit because no server sees the file. The real ceiling is your device memory, since the input and the output both have to fit in the tab. A few hundred megabytes is usually fine on a desktop machine and considerably less on a phone.
Can I convert several FLAC files at once?
Yes. Add as many as you like and they are processed one after another, then offered as separate Opus downloads or as a single ZIP. Speed depends on your own processor rather than on a queue.
Does the converter work offline?
Yes, after the page has loaded once. The engine is cached by the browser, so you can disconnect, reload and keep converting. That falls out of doing the work locally rather than being a separate mode you switch on.