Convert WMV to WMA — Free Online Tool
Convert WMV video files to WMA audio by extracting the Windows Media Audio stream and discarding the video track entirely. This is ideal for pulling audio from WMV recordings while staying within the Microsoft ecosystem, preserving the native wmav2 codec without unnecessary re-encoding.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your WMV file here
or click to browse
Free — no uploads, no signups. Your files never leave your browser.
Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
WMV files store video and audio in Microsoft's Advanced Systems Format (ASF) container, typically pairing an MSMPEG-4 video stream with a WMA audio stream encoded using the wmav2 codec. When converting to WMA, FFmpeg discards the video track completely and extracts only the audio stream, re-encoding it using wmav2 at the specified bitrate (128k by default). Because both WMV and WMA are built on the ASF container format and share the wmav2 codec, this conversion is essentially a demux-and-remux operation for the audio layer, meaning quality loss is minimal — the audio is decoded from the source wmav2 stream and re-encoded into a standalone WMA file at the target bitrate. No video processing occurs, which makes this conversion fast and computationally lightweight.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg command-line tool, which handles all media reading, processing, and writing. In this browser-based tool, FFmpeg runs locally via WebAssembly (ffmpeg.wasm) so no files leave your machine. |
-i input.wmv
|
Specifies the input WMV file. FFmpeg reads the ASF container, identifying both the MSMPEG-4 video stream and the wmav2 audio stream inside it. |
-c:a wmav2
|
Sets the audio codec for the output to wmav2, Microsoft's second-generation Windows Media Audio codec. This is the native and most compatible codec for WMA files, ensuring the output plays correctly in Windows Media Player and other WMA-compatible software. |
-b:a 128k
|
Sets the audio bitrate to 128 kilobits per second for the WMA output. This is the default balance between file size and audio quality for wmav2; you can raise this to 192k or 256k if the source WMV contained higher-quality audio and you want to preserve more detail. |
output.wma
|
Specifies the output filename with the .wma extension, which tells FFmpeg to write a Windows Media Audio file. FFmpeg automatically omits the video stream from the WMV source because the WMA container is audio-only and has no capacity for video data. |
Common Use Cases
- Extracting narration or commentary audio from WMV screen recordings or tutorial videos to archive as standalone WMA files for Windows Media Player libraries
- Pulling audio from WMV lecture recordings or corporate presentations to distribute as audio-only files to listeners who don't need the visual content
- Stripping the audio track from a WMV broadcast or streaming capture to create a WMA file compatible with Microsoft's DRM ecosystem for protected distribution
- Converting WMV video podcasts or video essays into WMA audio for playback on older Windows devices and media players that handle WMA natively but struggle with video playback
- Archiving the audio from WMV home videos or event recordings in a compact WMA format when the video quality is too poor to be worth keeping but the audio remains valuable
- Preparing WMA audio files from WMV source material for upload to platforms or workflows that specifically require Windows Media Audio format
Frequently Asked Questions
Some quality loss is possible because the audio is decoded from the source wmav2 stream and re-encoded into a new wmav2 WMA file. If the original WMV was encoded at a higher audio bitrate than the output's 128k default, you may notice a slight reduction in quality. To minimize this, set the output bitrate to match or exceed the original WMV's audio bitrate. If the source was already at 128k, the quality difference will be negligible.
The WMA format is a pure audio container — it has no support for video streams. FFmpeg automatically drops the video track when writing to a WMA output file because there is nowhere to put it. This is the intended behavior: WMA is designed for audio-only distribution, much like MP3 or AAC files.
Yes. If your WMV file is protected with Microsoft's Digital Rights Management (DRM), FFmpeg will not be able to read or process it, and the conversion will fail. DRM-protected WMV files restrict decoding to authorized playback software. This tool can only process unprotected WMV files. If your file plays freely in any media player without a license prompt, it is likely unprotected and will convert normally.
FFmpeg will attempt to copy metadata tags from the WMV source to the WMA output, since both formats use the ASF container which supports metadata tags. However, not all metadata fields map perfectly between formats, and some custom or extended tags may be dropped. Standard fields like title and artist have the best chance of transferring correctly.
Modify the -b:a flag in the command to set a different bitrate. For example, replace '-b:a 128k' with '-b:a 192k' or '-b:a 256k' for higher quality output. Supported WMA bitrate options include 64k, 96k, 128k, 160k, 192k, 256k, and 320k. Higher bitrates produce larger files but preserve more audio detail, which is especially worth doing if your source WMV had high-quality audio.
The command shown converts a single file, but you can adapt it for batch processing on your desktop. On Windows, wrap it in a for loop: 'for %f in (*.wmv) do ffmpeg -i "%f" -c:a wmav2 -b:a 128k "%~nf.wma"'. On Linux or macOS, use: 'for f in *.wmv; do ffmpeg -i "$f" -c:a wmav2 -b:a 128k "${f%.wmv}.wma"; done'. This is particularly useful for files over 1GB that exceed the browser tool's limit.
Technical Notes
Both WMV and WMA are built on Microsoft's Advanced Systems Format (ASF) container, which means they share the same underlying container structure. The wmav2 codec used in this conversion is the second generation of Microsoft's proprietary Windows Media Audio codec and is the standard choice for WMA output. WMV files can technically carry AAC or MP3 audio tracks instead of wmav2, but the majority of WMV files produced by Windows tools use wmav2 natively. If your source WMV happens to contain an AAC or MP3 audio track, FFmpeg will still transcode it to wmav2 for the WMA output. One important limitation: WMA does not support multiple audio tracks, so if the source WMV contains more than one audio stream (e.g., multiple language tracks), only the first/default stream will be written to the WMA file. Subtitles and chapter markers from the WMV are also silently discarded, as WMA supports neither. Because both the input and output use lossy compression, every encode-decode cycle introduces some generational quality loss — for archival purposes, keeping the original WMV alongside the WMA is advisable.