Convert Opus Audio Codec (.opus) to Free Lossless Audio Codec (.flac) online for free. Fast, secure audio conversion with no watermarks or registration.
Conversion settings — add a file to adjust
Upload your .opus file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .flac file when it's ready.
FLAC (Free Lossless Audio Codec) is the universal standard for lossless audio compression, supported on virtually every platform — Windows, macOS, Linux, Android, iOS (since iOS 11), and most dedicated audio players. Converting Opus to FLAC captures the full decoded audio from Opus's advanced compression algorithm into a losslessly compressed archive that can be reconverted to any format in the future without additional quality loss.
Opus, developed by Xiph.org and the IETF, is arguably the best lossy codec in existence, outperforming MP3, AAC, and Vorbis at every bitrate according to independent listening tests. However, it is still lossy — the encoding discards audio information deemed inaudible. By converting to FLAC, you preserve the maximum quality obtainable from the Opus decode in an open, patent-free format with the broadest possible platform support.
FLAC serves as the ideal archival format for decoded Opus audio because it compresses without discarding any data. If you have important Opus recordings — conference calls, interviews, podcast sessions, or musical performances recorded via WebRTC — converting to FLAC before any editing ensures that every processing step works from the highest-quality source available. FLAC files can be edited, processed, and re-exported to any lossy format (MP3, AAC, Vorbis) without the double-compression artifacts that occur when converting directly between lossy formats.
FLAC is also the required format for many online music stores (Bandcamp, Qobuz, 7digital), audiophile streaming services, and digital music distribution platforms. If you recorded audio via Opus and need to deliver it in lossless form, FLAC is the industry standard outside the Apple ecosystem.
FFmpeg decodes the Opus stream using libopus at its native 48 kHz sample rate and encodes it with the FLAC encoder at a selectable compression level (0-12, default 5). Higher compression levels produce smaller files but take longer to encode — the audio quality is identical regardless of level. The output is 16-bit or 24-bit at 44.1 kHz or 48 kHz. FLAC compression ratios for decoded Opus audio are typically 50-70% of the equivalent WAV size, depending on content complexity.
FLAC is mathematically lossless — the decoded PCM audio is preserved bit-for-bit. The quality ceiling is set by the Opus source encoding. A 128 kbps Opus file will produce a FLAC that sounds identical to the Opus but cannot be improved beyond what Opus captured. The advantage is that no further quality loss occurs, making FLAC ideal for archival and as a source for future conversions.
| Device | Opus | FLAC |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Native |
| Linux | Partial | Native |
| Web Browser | No |
Resolution: N/A
Bitrate: 320 kbps
OGG Vorbis preferred
Resolution: N/A
Bitrate: 256 kbps
AAC format required
Resolution: N/A
Bitrate: 128 kbps
Lossless FLAC/WAV for best quality
Resolution: N/A
Bitrate: 128 kbps
MP3 mono for spoken word
Opus to FLAC is the recommended path for archiving high-quality Opus recordings in the most universally supported lossless format. FLAC's open-source, patent-free nature and broad platform support make it the safest long-term storage choice for decoded Opus audio.
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| No |
| Ominaisuus | Opus | FLAC |
|---|---|---|
| Koko nimi | Opus Audio Codec | Free Lossless Audio Codec |
| Tiedostopääte | .opus | .flac |
| Paras käyttökohde | Low latency | Lossless compression |