WMA Files: Windows Media Audio Format Guide
WMA (Windows Media Audio) was Microsoft's answer to MP3 in the late 1990s. Introduced in 1999 as part of the Windows Media framework, WMA promised better audio quality than MP3 at the same or lower bitrates, along with built-in digital rights management (DRM) for copy protection. For a decade it was ubiquitous on Windows PCs, Zune devices, and Windows-compatible portable media players. While it has largely been supplanted by AAC, MP3, and now Opus for streaming and modern use, WMA files remain in millions of personal music libraries built during the 2000s and early 2010s.
WMA Variants
Microsoft developed several distinct WMA codecs under the same brand umbrella:
WMA Standard (WMA 7/8/9)
The most common variant. Files contain .wma extension. Supports bitrates from 5 to 768 kbps, sample rates from 8 to 48 kHz, and mono or stereo channels. WMA 9 (2003) added variable bitrate (VBR) and quality-based encoding modes and remains the most widely used WMA codec.
Typical uses: Music ripping from CDs, Windows Media Player downloads, Zune library.
Quality comparison: WMA Standard at 128 kbps offers roughly the same perceptual quality as MP3 at 128 kbps. At lower bitrates (64–96 kbps), WMA generally sounds better than MP3 but is outperformed by AAC-LC and Opus.
WMA Pro (WMA Professional)
Supports up to 7.1 surround channels, sample rates up to 96 kHz, and 24-bit sample depth. Designed for home theater and professional audio work. Files still use .wma but can be identified by the codec tag 0x0162.
Typical uses: Windows-based home theater PCs, Xbox 360 audio, some Blu-ray bonuses.
WMA Lossless
Lossless compression of PCM audio. Claims compression ratios of 1.7:1 to 3:1. Supports up to 24-bit/96 kHz and 7.1 channels. The file extension is .wma but codec tag is 0x0163.
Typical uses: Windows Media Center recordings, archival of CD rips where lossless quality is required.
WMA Voice
Very low-bitrate codec (4–20 kbps) optimized for voice recordings and dictation. Poor for music. Rarely used in modern applications.
DRM in WMA Files
WMA's DRM system (Windows Media DRM / PlayReady) locked purchased music to specific devices. Files purchased from MSN Music, Yahoo! Music, Rhapsody, and early Napster (post-legal) used WMA DRM and would only play on authorized devices. This caused widespread frustration when:
- Services shut down (MSN Music, Yahoo! Music)
- DRM servers went offline, making purchased music permanently unplayable
- Users tried to play files on non-Windows devices
DRM-free WMA files (ripped from CDs or downloaded from stores that dropped DRM after 2007) can be converted freely. DRM-protected WMA files cannot be legally transcoded without first removing the DRM — check the file properties in Windows Media Player to see if DRM is present.
Playing WMA Files
Windows: Windows Media Player plays WMA natively. Groove Music (Windows 10/11) and the Media Player app also support WMA out of the box.
macOS: iTunes/Music does not play WMA natively. QuickTime does not support WMA. Use VLC or IINA for playback, or convert to MP3/AAC first.
Linux: GStreamer with the gst-plugins-bad package provides WMA decoding. VLC and MPV handle WMA without additional setup.
iOS/Android: Neither natively supports WMA in the Music/Files apps. VLC for iOS and Android plays WMA files.
Smart speakers / streaming devices: Most do not support WMA. If you have a WMA music library and want to use it with Sonos, Chromecast Audio, or similar, convert to MP3 or FLAC first.
Converting WMA to Other Formats
WMA is not a format of the future. Converting to a more universal format (MP3, AAC, FLAC, Opus) ensures long-term compatibility.
WMA to MP3 (lossy → lossy — some quality loss):
ffmpeg -i input.wma -c:a libmp3lame -q:a 2 output.mp3
-q:a 2 targets VBR at approximately 190 kbps quality.
WMA to AAC (better quality at equivalent bitrate):
ffmpeg -i input.wma -c:a aac -b:a 192k output.m4a
WMA to FLAC (if source is WMA Lossless — preserves quality):
ffmpeg -i input.wma -c:a flac output.flac
WMA to Opus (best quality at low bitrates, recommended for streaming):
ffmpeg -i input.wma -c:a libopus -b:a 128k output.opus
Batch conversion (Windows Command Prompt):
for %f in (*.wma) do ffmpeg -i "%f" -c:a libmp3lame -q:a 2 "%~nf.mp3"
Batch conversion (Linux/macOS bash):
for f in *.wma; do
ffmpeg -i "$f" -c:a libmp3lame -q:a 2 "${f%.wma}.mp3"
done
WMA Lossless to FLAC Conversion
WMA Lossless files deserve special treatment. Since they are lossless, converting to FLAC preserves the original PCM data without any quality loss:
ffmpeg -i input_lossless.wma -c:a flac -compression_level 8 output.flac
Verify the conversion was lossless by checking the MD5 of the decoded PCM:
ffmpeg -i input_lossless.wma -f md5 -
ffmpeg -i output.flac -f md5 -
# Both MD5 values should match
Identifying WMA Codec Variant
To determine which WMA variant a file uses:
ffprobe -v quiet -print_format json -show_streams input.wma | grep codec
Look for:
wmav2→ WMA Standard (most common)wmapro→ WMA Professionalwmalossless→ WMA Losslesswmav1→ WMA v1 (very old, pre-2000)
Should You Keep WMA Files?
For personal music libraries built by ripping CDs:
- If files are WMA Standard at 128+ kbps and you have no other copy, keep them and convert to AAC or Opus for playback flexibility.
- If files are WMA Lossless and you want archival quality, convert to FLAC.
- If the original CD is available, consider re-ripping to FLAC or high-bitrate Opus rather than transcoding (transcoding lossy → lossy degrades quality slightly).
WMA was a technically respectable codec for its era, and many WMA files at 160–192 kbps sound indistinguishable from modern encoding. The issue is exclusively compatibility, not quality.
Related conversions
Audio format pairs that come up most often: