Convert MOV to WMV — Free Online Tool
Convert MOV files to WMV by re-encoding Apple QuickTime video through Microsoft's MPEG-4 variant (msmpeg4) with WMA audio (wmav2), producing an ASF-container file optimized for Windows Media Player and legacy Windows streaming workflows. This conversion bridges Apple's professional editing ecosystem with Microsoft's proprietary media infrastructure.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your MOV 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
MOV and WMV are fundamentally different containers with no codec overlap in practice, so this conversion requires full re-encoding of both the video and audio streams — not a simple remux. The video is decoded from its MOV source codec (commonly H.264/libx264) and re-encoded as msmpeg4, Microsoft's proprietary MPEG-4 variant implemented via the ASF (Advanced Systems Format) container. The audio is simultaneously transcoded from the MOV's native track (often AAC) into wmav2, the Windows Media Audio v2 codec. Several MOV features are lost in this process: subtitles, chapter markers, and transparency channels have no equivalent in WMV/ASF, and the output will be strictly lossy regardless of whether the source MOV used lossless compression. The -f asf flag explicitly forces the ASF container mux, which is what enables WMV compatibility with Windows-native players and older streaming infrastructure.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary to begin processing. This is the same engine running in your browser via WebAssembly — the command shown is 100% portable to a local FFmpeg installation. |
-i input.mov
|
Specifies the input QuickTime MOV file. FFmpeg will probe this file to detect its container structure, video codec (commonly H.264 or ProRes in MOV files), audio codec (commonly AAC), and any additional streams like subtitles or chapters. |
-c:v msmpeg4
|
Re-encodes the video stream using Microsoft's proprietary MPEG-4 variant (msmpeg4), which is the codec embedded inside WMV files and natively decoded by Windows Media Player. This is a full re-encode, not a copy, so every frame of the MOV video is decoded and recompressed. |
-c:a wmav2
|
Transcodes the audio stream to Windows Media Audio version 2, the standard audio codec for WMV/ASF files. The MOV source audio (typically AAC) is fully decoded and re-encoded, introducing a second generation of lossy compression. |
-b:v 2000k
|
Sets the target video bitrate to 2000 kilobits per second for the msmpeg4 output stream. Unlike MOV's CRF quality scale, WMV uses bitrate-based control — this value directly governs file size and visual quality, with higher values producing sharper output at the cost of larger files. |
-b:a 128k
|
Sets the WMA v2 audio output bitrate to 128 kilobits per second, which is a standard quality tier for stereo audio and appropriate for most speech and music content in WMV deliverables. |
-f asf
|
Explicitly forces the output container to ASF (Advanced Systems Format), the Microsoft container format that underlies all WMV files. Without this flag, FFmpeg might infer the container from the .wmv extension, but explicit declaration ensures reliable muxing especially in scripted workflows. |
output.wmv
|
Defines the output filename. The .wmv extension signals that this is a Windows Media Video file backed by the ASF container, and is the format expected by Windows Media Player and legacy Microsoft streaming services. |
Common Use Cases
- Submitting video content to corporate intranets or legacy enterprise media servers that only accept Windows Media Video files from macOS-produced MOV footage
- Delivering edited QuickTime exports to clients who use Windows XP/7-era machines where Windows Media Player is the only available video player
- Converting Apple Final Cut Pro or iMovie MOV exports for playback on older Windows-based digital signage systems that require WMV input
- Archiving or sharing screen recordings made on macOS (which default to MOV) with Windows users in environments where WMV is the agreed distribution format
- Preparing video content for embedding in older Microsoft PowerPoint presentations on Windows, where WMV has historically had the best native insertion support
- Batch-converting a library of QuickTime footage to WMV to meet legacy streaming platform requirements tied to Microsoft's Windows Media Services infrastructure
Frequently Asked Questions
Yes — this conversion always involves quality loss, regardless of the quality of your source MOV. WMV is a strictly lossy format, and the msmpeg4 codec used here is a generation behind modern codecs like H.264 or H.265. The default bitrate of 2000k (-b:v 2000k) is adequate for standard-definition content but will produce visible degradation on high-resolution or high-motion footage compared to the original. If your MOV was already H.264 with a higher bitrate, expect a noticeable quality drop, especially at high resolutions.
No. The WMV format uses the ASF container, which does not support embedded subtitle tracks or chapter markers in the way MOV does. Any subtitles or chapters present in your source MOV file will be silently dropped during conversion. If preserving subtitles is important, you should extract them separately as an SRT file before converting, using a tool like FFmpeg with '-map 0:s' to export the subtitle stream.
No. WMV/ASF does not support alpha channel transparency at all, and the msmpeg4 codec has no mechanism for encoding transparency data. Any transparent regions in your source MOV will be composited against a black background in the WMV output. If transparency is required in your output, WMV is not a suitable target format — consider WebM with VP9 or MOV with PNG codec instead.
Replace the value after -b:v in the command. For example, use '-b:v 1000k' for a smaller file with lower quality, or '-b:v 4000k' for higher quality at larger file size. Unlike MOV's CRF-based encoding, WMV uses constant bitrate control via -b:v, so you are directly specifying a target data rate rather than a quality level. For most web-delivery or email-sharing use cases, 1000k to 2000k is the practical range for the msmpeg4 codec.
Yes, with a small shell script. On Linux or macOS, run: for f in *.mov; do ffmpeg -i "$f" -c:v msmpeg4 -c:a wmav2 -b:v 2000k -b:a 128k -f asf "${f%.mov}.wmv"; done. On Windows Command Prompt, use: for %f in (*.mov) do ffmpeg -i "%f" -c:v msmpeg4 -c:a wmav2 -b:v 2000k -b:a 128k -f asf "%~nf.wmv". Each MOV file will be individually re-encoded to a WMV output, so processing time scales linearly with the number and size of files.
While FFmpeg can often infer the output container from the file extension, explicitly specifying '-f asf' ensures the output is correctly muxed into the Advanced Systems Format container that WMV requires, regardless of environment or FFmpeg build. WMV is essentially a branded subset of ASF with specific codec pairings (msmpeg4 video + wmav2 audio), and the -f asf flag makes this container selection unambiguous, which is particularly important when running the command in automated or scripted pipelines where relying on extension inference could cause silent muxer mismatches.
Technical Notes
The msmpeg4 codec used in this conversion is Microsoft's proprietary variant of MPEG-4 Part 2, distinct from the ISO-standard MPEG-4 (libxvid or mpeg4 in FFmpeg terms) and significantly older than H.264. It is not hardware-accelerated on any modern GPU, making encoding slower and output quality lower per bit compared to H.264 or H.265. The WMA v2 (wmav2) audio codec is a reasonable-quality lossy codec at 128k but lacks the efficiency of AAC or Opus at the same bitrate. Metadata such as title, artist, and creation date embedded in the MOV file may partially survive into the ASF container's metadata fields, but field mapping is inconsistent and tools like Windows Media Player may not display them correctly. Multiple audio tracks are technically supported by ASF, but most WMV players only expose the first audio track to users. Color space handling is an important consideration: MOV files from professional cameras often use BT.709 or even BT.2020 color spaces, and FFmpeg may not correctly signal the color space in the ASF output, potentially causing subtle color shifts in the WMV file when viewed in Windows Media Player. For high-quality archival purposes, WMV is not recommended as a target format — consider MP4 with H.264 if broad compatibility is the goal.