Add your FLAC file
Drop one or more .flac 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.
FLAC to OPUS
Re-encoding .flac audio as .opus changes how the sound is compressed and which players will accept it. Free, private, and validated — the file never leaves your browser.
100% private for supported formats
Runs on your deviceConvert supported files
Drop FLAC 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 FLAC audio to Opus audio
Re-encoding .flac audio as .opus changes how the sound is compressed and which players will accept it. 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.
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. For this route the practical draw is best-in-class efficiency at essentially every bitrate and royalty-free with an open reference implementation — balanced against older car stereos, AV receivers, and MP3 players have never heard of it, which is worth knowing before you commit a large batch.
Why convert FLAC to OPUS?
The practical trigger for this conversion is usually a mismatch: with .flac, still several times larger than a good lossy encode. Switching to .opus buys you best-in-class efficiency at essentially every bitrate, which is why it is the better fit for compressing podcast and voice-chat audio to tiny files. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
FLAC vs OPUS at a glance
| Aspect | FLAC audio (.flac) | Opus audio (.opus) |
|---|---|---|
| Format type | Lossless — every pixel or sample is preserved exactly | Lossy — discards detail it judges invisible to shrink files |
| How it stores data | linear prediction followed by Rice coding typically yields files 40 to 60 percent the size of raw PCM | the hybrid SILK/CELT design switches coding modes automatically based on content |
| Strongest at | ripping CD collections for permanent archival | compressing podcast and voice-chat audio to tiny files |
| Weak spot | still several times larger than a good lossy encode | older car stereos, AV receivers, and MP3 players have never heard of it |
| Metadata | vorbis comments for tags plus a dedicated PICTURE block for cover art; cue sheets can be embedded for whole-disc rips | vorbis comments in the OpusTags header, including cover art via METADATA_BLOCK_PICTURE, plus an output-gain field used for loudness normalization |
Pick OPUS as the output
Select .opus in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if OPUS 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 OPUS file. Outputs keep the original filename with the .opus extension.
FLAC to OPUS questions, answered
Will converting FLAC to OPUS lose quality?
Some. Since flac is lossless-oriented and opus is lossy-oriented, the encoder will discard detail it judges least visible; the quality slider controls how aggressive that is. Keep the original .flac if you may need a pristine master later.
Is it private to convert FLAC files here?
Yes — the .flac 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 OPUS file work?
Chrome, Firefox, and Edge have played Opus for a decade and Android supports it natively, while Safari initially accepted the codec only inside CAF or WebM wrappers before extending support to .opus files. Legacy hardware such as older car head units remains the real gap, and conversion to MP3 or AAC bridges it.
Will the OPUS file be bigger or smaller than my FLAC?
Smaller, usually dramatically so — that is the main reason this route exists. The quality slider trades size against fidelity; the default sits at the point where most people cannot spot the difference.
What happens to the metadata in my FLAC 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 for tags plus a dedicated PICTURE block for cover art; cue sheets can be embedded for whole-disc rips; none of it is transmitted anywhere because the file never leaves your browser.
Can I convert OPUS back to FLAC?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .flac → .opus → .flac is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.