Step 1: Provide your FLAC files using the button above or by toss and let go.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Fetch your converted Opus files.
FLAC to Opus Conversion FAQ
What bitrate does the Opus file end up at?
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A lossy Opus is encoded at 192 kbps by default. The Audio Quality setting also offers 320 kbps for the best quality and 128 kbps for a smaller file. A lossless Opus (WAV, FLAC) ignores the bitrate and keeps every sample.
How much quality do I lose converting FLAC to Opus?
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Some, and it is permanent — this is the one direction where information is genuinely thrown away. FLAC holds every sample exactly; Opus discards what a psychoacoustic model predicts you will not hear. At 192 kbps and above that prediction is good enough to be transparent on most material and most equipment. Keep the FLAC as your master, because you cannot get back to it from the Opus. FLAC uses linear prediction plus Rice coding to reach roughly 50-60% of the original size while decoding back to bit-identical PCM. Opus scales from 6 kbps mono speech to 510 kbps stereo music in the same bitstream and switches modes automatically.
Will going from FLAC to Opus actually reduce my audio quality?
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If FLAC is lossy (MP3, AAC) and Opus is lossless (WAV, FLAC), the Opus is no better than the FLAC — you cannot recover information already discarded by the lossy FLAC codec. If FLAC is lossless and Opus is lossy, expect the Opus encoder to recompress; at 192 kbps the loss is imperceptible to most ears.
Can I batch-convert hundreds of FLAC files into Opus?
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Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.
Can I normalize loudness in the FLAC to Opus step?
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Not in this step. The converter has no loudness setting and leaves the level as it is. To even out the volume, run the finished Opus through a Normalize tool on this site.
Will the Opus play on my car stereo / iPod / Sonos / Bluetooth speaker?
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MP3 plays almost everywhere. AAC plays on Apple devices, most Android phones and Sonos. FLAC plays on Sonos and Android but not on older iPods, and WAV plays on nearly everything but makes large files. There are no device presets on this page, so choose the target format your player supports. Opus is the best-sounding lossy codec at low bitrates by a clear margin, and it powers WhatsApp voice notes, Discord and WebRTC. Opus is almost never supported by standalone hardware — assume software playback only, and expect car stereos to ignore it.
Is my FLAC file private during conversion?
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Yes. Uploaded FLAC files are processed on our own conversion servers, no person reviews them, and they are never shared. The upload and the converted Opus are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy.
How long does converting a 1-hour FLAC to Opus take?
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It depends on the size and length of the file. Small documents and images are usually ready quickly. Long videos take the longest, because most video conversions re-encode every frame.
Why is the Opus file louder or quieter than the FLAC source?
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The converter does not change the level: it has no gain or normalize setting. If you hear a difference, your player or media library is probably applying ReplayGain or its own volume levelling on playback; switch that off to hear the Opus as it is.
