WMA (Windows Media Audio)
Microsoft's answer to MP3: a proprietary audio codec built for Windows that still lives on millions of devices today.
| Full name | Windows Media Audio |
| Extension | .wma |
| MIME type | audio/x-ms-wma |
| Developer | Microsoft |
| Released | 1999 (as part of Windows Media Technologies 4.0) |
| Type | Lossy audio compression (also lossless and voice variants) |
| Container | Advanced Systems Format (ASF) |
| Bitrate range | 48 kbps to 192 kbps (standard); up to 768 kbps (WMA Pro) |
What is a WMA file?
WMA is a proprietary audio format created by Microsoft in 1999 as a direct competitor to MP3 and RealAudio. Audio encoded in WMA is stored inside an Advanced Systems Format (ASF) container. It was the default format for ripping CDs in Windows Media Player for many years, which put it on millions of PCs worldwide.
WMA is actually a family of four distinct codecs sharing the same file extension. Standard WMA is a lossy codec aimed at general music playback. WMA Pro handles multichannel and high-resolution audio up to 7.1 channels and 24-bit depth. WMA Lossless compresses audio without any quality loss, similar to FLAC. WMA Voice targets spoken-word content at very low bitrates. All four store their output in the .wma container, so the extension alone does not tell you which codec was used.
History
Microsoft introduced WMA in 1999 with version 1, quickly followed by WMA 2 the same year with minor bitstream changes; both shipped as part of Windows Media Technologies 4.0. The format gained wide traction in the early 2000s when Windows Media Player became the default ripping tool in Windows XP, and by 2002 leading DVD manufacturers were announcing WMA playback support in consumer hardware. In 2003, Microsoft released the WMA 9 Professional, WMA 9 Lossless, and WMA 9 Voice codecs, which are incompatible with the original WMA codec and require a newer decoder.
How it works
A WMA file is an ASF container, which is a binary format built around a sequence of header and data objects. The header object describes the stream properties, codec information, content description, and DRM licensing data if present. Audio frames follow in the data section, encoded with the selected WMA codec variant. Because ASF is a general-purpose container, the same format can carry video streams alongside audio, though a .wma file conventionally holds audio only.
What it is used for
- Playing back music ripped with Windows Media Player on Windows XP, Vista, or 7 machines
- Distributing DRM-protected audio files tied to specific devices or playback licenses
- Archiving spoken-word content at very low bitrates using the WMA Voice variant
- Streaming high-resolution multichannel audio in Windows-based home theater setups using WMA Pro
How to open it
WMA files open natively in Windows Media Player and the modern Windows Media app on Windows 10 and 11. On macOS, Linux, and mobile platforms, VLC handles WMA reliably; many Android music players support it, but iOS devices require a third-party app since Apple's native players do not support WMA.
Pros and cons
Strengths
- Built into every Windows PC — no extra software needed for basic playback on Windows
- DRM support lets publishers control who can play, copy, or transfer a file
- WMA Lossless offers bit-perfect audio quality for archiving without the patent concerns of older formats
- Wide hardware support on older portable media players and car stereos from the 2000s
Trade-offs
- Proprietary format with no native playback on macOS, iOS, or many Android devices without a third-party player
- DRM-protected WMA files can become unplayable if the license server shuts down or the device is changed
- Modern alternatives like AAC and Opus deliver better quality at equivalent bitrates
- WMA Pro and WMA Lossless are rarely supported outside of Windows, limiting their practical reach
Convert WMA files
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From WMA
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WMA FAQ
Can I play a WMA file on a Mac or iPhone?
Not without extra software. macOS and iOS do not include a WMA decoder natively. VLC for Mac or a third-party app like Infuse on iOS will play most WMA files. The easiest long-term fix is to convert the file to AAC or MP3.
Is WMA better quality than MP3?
At the same bitrate, WMA is generally considered equal to or slightly better than MP3, particularly below 128 kbps. Modern codecs like AAC and Opus outperform both at equivalent bitrates, so for new recordings there is little reason to choose WMA.
What happens to a DRM-protected WMA file if I convert it?
DRM-protected WMA files cannot be converted directly — the DRM wrapper blocks third-party decoders. You need to either obtain a DRM-free version from the original source or, where legally permitted, use a tool that can remove the DRM protection before converting.
What is the difference between WMA and WMA Lossless?
Standard WMA discards audio data to shrink the file size, similar to MP3. WMA Lossless compresses audio without losing any data, so decoding it produces a bit-for-bit copy of the original. WMA Lossless files are much larger but are suitable for archiving where quality cannot be compromised.