Add your OPUS file
Drop one or more .opus files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
OPUS to FLAC
Re-encoding .opus audio as .flac changes how the sound is compressed and which players will accept it. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop OPUS files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting Opus audio to FLAC audio
Re-encoding .opus audio as .flac changes how the sound is compressed and which players will accept it. An .opus file contains audio compressed with the Opus codec, stored in an Ogg container. Opus represents the current state of the art in lossy audio, beating MP3, AAC, and Vorbis in listening tests at nearly every bitrate from whisper-thin speech settings up to transparent music encoding.
A .flac file contains audio compressed with the Free Lossless Audio Codec, which shrinks recordings without discarding a single sample. Decoded .flac output is bit-identical to the source, so the format has become the standard for music archiving and high-resolution downloads. For this route the practical draw is genuinely lossless while roughly halving storage and open specification with no royalties anywhere in the chain — balanced against still several times larger than a good lossy encode, which is worth knowing before you commit a large batch.
Why convert OPUS to FLAC?
The practical trigger for this conversion is usually a mismatch: with .opus, older car stereos, AV receivers, and MP3 players have never heard of it. Switching to .flac buys you genuinely lossless while roughly halving storage, which is why it is the better fit for ripping CD collections for permanent archival. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
OPUS vs FLAC at a glance
| Aspect | Opus audio (.opus) | FLAC audio (.flac) |
|---|---|---|
| Format type | Lossy — discards detail it judges invisible to shrink files | Lossless — every pixel or sample is preserved exactly |
| How it stores data | the hybrid SILK/CELT design switches coding modes automatically based on content | linear prediction followed by Rice coding typically yields files 40 to 60 percent the size of raw PCM |
| Strongest at | compressing podcast and voice-chat audio to tiny files | ripping CD collections for permanent archival |
| Weak spot | older car stereos, AV receivers, and MP3 players have never heard of it | still several times larger than a good lossy encode |
| Metadata | vorbis comments in the OpusTags header, including cover art via METADATA_BLOCK_PICTURE, plus an output-gain field used for loudness normalization | vorbis comments for tags plus a dedicated PICTURE block for cover art; cue sheets can be embedded for whole-disc rips |
Pick FLAC as the output
Select .flac in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if FLAC is selectable, the route is real and validated.
Convert on your device
Press Convert. The transcode runs on an FFmpeg engine compiled to WebAssembly, so the audio never leaves your device.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid FLAC file. Outputs keep the original filename with the .flac extension.
OPUS to FLAC questions, answered
Will converting OPUS to FLAC lose quality?
No new loss is introduced — since opus is lossy-oriented and flac is lossless-oriented, everything the .opus file still contains is carried over exactly. What was already discarded by the original lossy encode cannot be recovered, though; converting to .flac does not "restore" quality.
Is it private to convert OPUS files here?
Yes — the .opus file is processed inside your browser tab and never uploaded. The transcode runs on an FFmpeg engine compiled to WebAssembly, so the audio never leaves your device. Close the tab and the file is gone from memory.
Where will the FLAC file work?
All major browsers decode .flac, Windows 10 and later plus Android play it natively, and virtually every dedicated audio player supports it. The persistent gap is Apple's Music ecosystem, where converting to ALAC delivers the same audio in a supported wrapper.
Will the FLAC file be bigger or smaller than my OPUS?
Larger, sometimes much larger. A lossless .flac must store every pixel or sample the decoder produced, without the perceptual shortcuts .opus used. Use this route for editing headroom, not for saving space.
What happens to the metadata in my OPUS file?
This converter strips container metadata deliberately (the FFmpeg command runs with metadata mapping disabled) so exported files do not leak recording details. In the source, vorbis comments in the OpusTags header, including cover art via METADATA_BLOCK_PICTURE, plus an output-gain field used for loudness normalization; none of it is transmitted anywhere because the file never leaves your browser.
Can I convert FLAC back to OPUS?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .opus → .flac → .opus is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.