Add your M4A file
Drop one or more .m4a 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.
M4A to WMA
Re-encoding .m4a 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 M4A 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 MPEG-4 audio to Windows Media audio
Re-encoding .m4a audio as .wma changes how the sound is compressed and which players will accept it. An .m4a file is an MPEG-4 container that holds only audio, most often AAC and occasionally Apple Lossless. Apple coined the .m4a extension so audio would not be confused with .mp4 video, and it remains the default for iTunes purchases, Apple Music downloads, and Voice Memos.
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 M4A to WMA?
The practical trigger for this conversion is usually a mismatch: with .m4a, the extension hides whether the contents are lossy or lossless, muddying quality expectations. 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.
M4A vs WMA at a glance
| Aspect | MPEG-4 audio (.m4a) | 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 | an ISO base media container restricted to audio tracks, structurally a sibling of MP4 | the standard codec is a lossy transform coder supporting up to 48 kHz stereo |
| Strongest at | managing music inside iTunes and Apple Music libraries | converting old ripped-CD libraries to MP3 or FLAC |
| Weak spot | the extension hides whether the contents are lossy or lossless, muddying quality expectations | proprietary and effectively abandoned |
| Metadata | iTunes-style metadata atoms: title, album, artwork, composer, BPM, and the iTunSMPB gapless-playback data | 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.
M4A to WMA questions, answered
Will converting M4A to WMA lose quality?
A second lossy step always costs a little, because m4a 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 .m4a and .wma.
Is it private to convert M4A files here?
Yes — the .m4a 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 M4A?
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 M4A 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, iTunes-style metadata atoms: title, album, artwork, composer, BPM, and the iTunSMPB gapless-playback data; none of it is transmitted anywhere because the file never leaves your browser.
Can I convert WMA back to M4A?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .m4a → .wma → .m4a is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.