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 WMA
Re-encoding .opus audio as .wma 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 Windows Media audio
Re-encoding .opus audio as .wma 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 .wma file contains Windows Media Audio, Microsoft's proprietary compressed format, wrapped in the same ASF container as WMV video. It shipped with every copy of Windows for a decade, so ripped CDs and store purchases from that era survive as .wma libraries. For this route the practical draw is respectable quality at mid bitrates for its era and still opens on any Windows PC without extra software — balanced against proprietary and effectively abandoned, which is worth knowing before you commit a large batch.
Why convert OPUS to WMA?
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 .wma buys you respectable quality at mid bitrates for its era, which is why it is the better fit for converting old ripped-CD libraries to MP3 or FLAC. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
OPUS vs WMA at a glance
| Aspect | Opus audio (.opus) | Windows Media audio (.wma) |
|---|---|---|
| Format type | Lossy — discards detail it judges invisible to shrink files | Lossy — discards detail it judges invisible to shrink files |
| How it stores data | the hybrid SILK/CELT design switches coding modes automatically based on content | the standard codec is a lossy transform coder supporting up to 48 kHz stereo |
| Strongest at | compressing podcast and voice-chat audio to tiny files | converting old ripped-CD libraries to MP3 or FLAC |
| Weak spot | older car stereos, AV receivers, and MP3 players have never heard of it | proprietary and effectively abandoned |
| Metadata | vorbis comments in the OpusTags header, including cover art via METADATA_BLOCK_PICTURE, plus an output-gain field used for loudness normalization | aSF attributes mirror ID3 basics such as title, artist, album, and artwork, and Windows Media Player wrote extended library fields on top |
Pick WMA as the output
Select .wma in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if WMA 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 WMA file. Outputs keep the original filename with the .wma extension.
OPUS to WMA questions, answered
Will converting OPUS to WMA lose quality?
A second lossy step always costs a little, because opus is lossy-oriented and wma is lossy-oriented and each encoder discards detail differently (generation loss). At the default quality the difference is rarely visible; avoid repeated round-trips between .opus and .wma.
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 WMA file work?
Windows continues to play .wma through its bundled apps, but macOS, iOS, Android, and all web browsers lack native support. Files protected by Windows Media DRM will not play anywhere now that their license servers are gone.
Will the WMA file be bigger or smaller than my OPUS?
It depends on the content: the standard codec is a lossy transform coder supporting up to 48 kHz stereo. Convert one representative file first and compare before batch-processing a large set.
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 WMA back to OPUS?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .opus → .wma → .opus is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.