Add your AAC file
Drop one or more .aac 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.
AAC to WMA
Re-encoding .aac 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 AAC 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 AAC audio to Windows Media audio
Re-encoding .aac audio as .wma changes how the sound is compressed and which players will accept it. An .aac file holds raw Advanced Audio Coding data, usually as an ADTS stream. AAC was designed as MP3's successor and delivers audibly better quality at the same bitrate, though the bare .aac extension is rarer than AAC audio traveling inside .m4a or .mp4 files.
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 AAC to WMA?
The practical trigger for this conversion is usually a mismatch: with .aac, raw ADTS files handle tags and cover art poorly. 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.
AAC vs WMA at a glance
| Aspect | AAC audio (.aac) | 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 | a pure MDCT transform codec, free of the hybrid filterbank compromise that limited MP3 | the standard codec is a lossy transform coder supporting up to 48 kHz stereo |
| Strongest at | receiving the audio track copied out of MP4 video without re-encoding | converting old ripped-CD libraries to MP3 or FLAC |
| Weak spot | raw ADTS files handle tags and cover art poorly | proprietary and effectively abandoned |
| Metadata | no standard tag container exists for raw ADTS streams; ID3 tags are sometimes prepended but poorly supported, so wrapping in .m4a is the reliable way to tag AAC | 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.
AAC to WMA questions, answered
Will converting AAC to WMA lose quality?
A second lossy step always costs a little, because aac 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 .aac and .wma.
Is it private to convert AAC files here?
Yes — the .aac 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 AAC?
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 AAC 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, no standard tag container exists for raw ADTS streams; ID3 tags are sometimes prepended but poorly supported, so wrapping in .m4a is the reliable way to tag AAC; none of it is transmitted anywhere because the file never leaves your browser.
Can I convert WMA back to AAC?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .aac → .wma → .aac is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.