What is the WMA file format?
.wma is an audio file format developed by Microsoft. Each .wma file stores an audio track along with related metadata, such as track name, track number, author, and music genre. .wma files use the Advanced Systems Format (ASF) container - the same container also used by .wmv and .asf files. .wma files are typically smaller than other comparable formats at the same perceptible quality level.
The format comes in several codec variants, all sharing the .wma extension:
- WMA Standard - lossy, MDCT-based compression; the most common variant
- WMA Lossless - bit-perfect compression for archival use
- WMA Pro - up to 7.1 surround sound and 96 kHz sample rate
- WMA Voice - low-bitrate speech encoding
WMA format was created as a result of a patent conflict between the creator of the MP3 format and Microsoft, which wanted a codec it controlled. Microsoft claimed for some time that WMA offers audio quality comparable to that of audio CD, yet many independent tests proved the claim unsubstantiated. However, the tests showed that the format offered slightly better audio quality than MP3 encoding at equivalent bitrates.
Some .wma files - particularly older downloads from music or audiobook stores - carry Windows Media DRM protection (WMDRM/PlayReady). DRM-locked files will not play or convert without the original licence, which is the most common cause of .wma playback problems. The format has since been largely displaced by MP3, AAC, and Opus; Microsoft itself now defaults to AAC in newer applications.
Security & safety
RISK: LOWA plain WMA audio file is passive and low-risk. Two real-world snags: (1) DRM-protected WMA (old store/audiobook downloads) won't play or convert without the original licence - that is a rights restriction, not a virus; (2) searching for 'WMA to MP3 converter' surfaces many adware-bundling installers and fake 'DRM removers' - stick to VLC or Audacity. As always, only open audio files from sources you trust.
Format details
in a nutshellPrograms that open WMA files
Windows3 apps
VLC media player
Open-source Open with VLC; plays WMA (including most non-DRM variants) with no codec packs. 
Windows Media Player / Media Player
Built-in Double-click the .wma - the built-in Media Player app (Windows 11) or Windows Media Player plays it natively. 
macOS1 app
VLC media player
Open-source Open the .wma in VLC - QuickTime no longer handles WMA, so VLC is the go-to on Mac. 
Linux1 app
Android1 app
VLC for Android
Open-source Open the .wma in VLC; native Android audio often can't decode WMA, VLC can.
VLC for Mobile
Open-source Add the .wma to VLC via Files/iTunes/cloud and play - iOS has no native WMA support. Technical details
deep spec| Container format | ASF (Advanced Systems Format); the 16-byte ASF Header Object GUID (30 26 B2 75 …) at offset 0 is shared with .asf and .wmv files |
| MIME type | audio/x-ms-wma (also recognised: audio/wma, audio/x-wma) |
| Byte order | Little-endian |
| Compression algorithm | MDCT-based lossy (WMA Standard/Pro); integer-to-integer lossless transform (WMA Lossless); CELP-variant low-bitrate codec (WMA Voice) |
| Codec variants | WMA1/WMA2 (Standard), WMA9, WMA10 Pro, WMA Lossless, WMA Voice - each identified by a unique codec GUID in the ASF Stream Properties Object |
| Sample rate | 8 kHz-48 kHz (WMA Standard); up to 96 kHz (WMA 10 Pro) |
| Channel support | Mono/stereo (WMA Standard); up to 7.1 surround (WMA Pro) |
| Typical bitrate | 32-192 kbps lossy (Standard); 470-940 kbps (Lossless); 4-20 kbps (Voice) |
| DRM support | Optional Windows Media DRM (WMDRM) or PlayReady; licence-bound files will not play or convert on unlicensed devices |
| Metadata storage | ASF Content Description and Extended Content Description objects; supports title, artist, album, genre, track number, and embedded album art |
| Typical file size | ~0.5-1 MB per minute at 128 kbps; scales with bitrate and codec variant |
| Integrity mechanism | Per-packet ASF headers; no whole-file checksum; DRM variant adds a digital signature |
| Magic bytes (hex) | 30 26 B2 75 8E 66 CF 11 A6 D9 00 AA 00 62 CE 6C at offset 0 (ASF Header Object GUID) |
| Platform origin | Windows; natively decoded by Windows Media Player 6.4+ and Windows 7-11 built-in Media Player |
| Released | 1999 (Windows Media Audio, with Windows Media Player 6.4 / Windows Media Technologies 4) |
| Latest version | WMA 10 Pro / WMA 9.2 codecs (Windows Media 9 series era); WMA Lossless and WMA Voice variants |
| Specification | learn.microsoft.com |
WMA conversions
Community Q&A
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