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 ALAC
Re-encoding .opus audio as .alac 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 Apple Lossless audio
Re-encoding .opus audio as .alac 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.
ALAC, the Apple Lossless Audio Codec, compresses music with zero quality sacrifice, and the .alac extension is occasionally used to label such files explicitly even though the codec normally travels inside an .m4a container. Decoding reproduces the original samples exactly, making it Apple's counterpart to FLAC. For this route the practical draw is native on every Apple platform from iOS to HomePod and mathematically lossless reconstruction — balanced against compresses slightly worse than FLAC on average, which is worth knowing before you commit a large batch.
Why convert OPUS to ALAC?
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 .alac buys you native on every Apple platform from iOS to HomePod, which is why it is the better fit for building a lossless library that syncs cleanly to iPhones and the Music app. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
OPUS vs ALAC at a glance
| Aspect | Opus audio (.opus) | Apple Lossless audio (.alac) |
|---|---|---|
| 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 compression conceptually similar to FLAC, typically reaching 40 to 60 percent of PCM size |
| Strongest at | compressing podcast and voice-chat audio to tiny files | building a lossless library that syncs cleanly to iPhones and the Music app |
| Weak spot | older car stereos, AV receivers, and MP3 players have never heard of it | compresses slightly worse than FLAC on average |
| Metadata | vorbis comments in the OpusTags header, including cover art via METADATA_BLOCK_PICTURE, plus an output-gain field used for loudness normalization | inherits the full iTunes metadata atom set from its MPEG-4 container, including artwork, composer, and grouping fields |
Pick ALAC as the output
Select .alac in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if ALAC 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 ALAC file. Outputs keep the original filename with the .alac extension.
OPUS to ALAC questions, answered
Will converting OPUS to ALAC lose quality?
No new loss is introduced — since opus is lossy-oriented and alac 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 .alac 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 ALAC file work?
Every Apple device and application plays ALAC natively, and cross-platform players such as VLC and foobar2000 handle it on Windows, Linux, and Android. Outside the Apple world support varies by player, which is why cross-platform archives still tend to favor FLAC.
Will the ALAC file be bigger or smaller than my OPUS?
Larger, sometimes much larger. A lossless .alac 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 ALAC back to OPUS?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .opus → .alac → .opus is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.