WMA vs Y4M
A detailed comparison of Windows Media Audio and YUV4MPEG2 — file size, quality, compatibility, and which format to choose for your workflow.
Windows Media Audio
Audio FilesWMA is a proprietary Microsoft audio format from the Windows Media framework. Once common in the Windows ecosystem, it has been largely replaced by AAC and MP3 for general use.
About WMA filesYUV4MPEG2
Video FilesYUV4MPEG2 (Y4M) is a simple uncompressed video format that stores raw YUV pixel data with a minimal header. It is widely used as an intermediate format for video processing and quality benchmarking where no compression artifacts are acceptable.
About Y4M filesStrengths Comparison
WMA Strengths
- Good quality at low bitrates (32-64 kbps) — outperformed MP3 in that range.
- Native playback on every Windows version 2000 through 10.
- Lossless variant available (WMA Lossless) for archiving.
- Supports multichannel 5.1 surround audio.
Y4M Strengths
- Uncompressed raw YUV — codec benchmark truth.
- Dead-simple header.
- Universal codec development support.
Limitations
WMA Limitations
- Proprietary — poor support outside Windows and Windows Media Player.
- DRM variants made files brittle — many purchased tracks became unplayable when stores shut down.
- Ecosystem abandoned — no modern editors, hardware decoders, or streaming services use WMA.
- Windows 11 deprecated Windows Media Player entirely.
Y4M Limitations
- Enormous file sizes.
- Development-only — not for consumption.
- No metadata beyond basic stream params.
Technical Specifications
| Specification | WMA | Y4M |
|---|---|---|
| MIME type | audio/x-ms-wma | video/x-yuv4mpeg2 |
| Extension | .wma | .y4m |
| Container | ASF (Advanced Systems Format) | — |
| Variants | WMA Standard, WMA Pro, WMA Lossless, WMA Voice | — |
| Max bitrate | 768 kbps (WMA Pro) | — |
| Pixel format | — | YUV 4:2:0, 4:2:2, 4:4:4 |
| Header | — | ASCII single line |
Typical File Sizes
WMA
- 3-min song (128 kbps) 3 MB
- 3-min song (Lossless) 25-35 MB
- 1-hour talk (64 kbps) 28 MB
Y4M
- 10 sec 1080p Y4M ~600 MB
- 1 min 4K Y4M ~14 GB
Ready to convert?
Convert between WMA and Y4M online, free, and without installing anything. Encrypted upload, automatic deletion after 2 hours.
Frequently Asked Questions
WMA (Windows Media Audio) is an audio file format used to store sound recordings — music, voice, podcasts, sound effects. The format defines how the audio samples are compressed (or stored raw), what bitrates are supported, and how metadata such as title, artist, album, and cover art is embedded. It is part of the audio files family.
Y4M (YUV4MPEG2) is a video container format that bundles one or more video streams, audio tracks, and optional subtitles into a single file. The container format determines how metadata is organised and which codecs can live inside; the visual quality itself depends on the codec (H.264, H.265, VP9, AV1) rather than the Y4M wrapper. It is part of the video files family.
VLC, foobar2000, and the default media players on Windows and macOS handle WMA natively. On mobile, iOS Music and Android media apps vary in their support — popular formats work everywhere; niche ones may need a dedicated app. If playback fails on a device, converting to MP3 or AAC usually solves it.
VLC, MPV and PotPlayer play nearly every Y4M file on desktop. Browser support varies: modern Chromium, Firefox and Safari play common containers via the HTML5 <video> tag, but niche Y4M variants may fail. If a device refuses your Y4M, convert to MP4 with our Y4M to MP4 converter for universal playback.
Upload the WMA to KaijuConverter and pick MP3, WAV, FLAC, AAC, OGG, or any other target. Our FFmpeg pipeline decodes the audio and re-encodes to the target format at sensible default bitrates (VBR ~190 kbps for music, 96 kbps for speech). Metadata and cover art travel with the audio where both formats support them.
WMA can be lossy or lossless depending on the specific variant. Lossy variants (smaller files) discard some audio detail during compression in ways tuned to be inaudible; lossless variants preserve every sample exactly but produce larger files. For distribution, lossy at high bitrate is standard; for archival, lossless wins.