What happens when you convert MP4 to WMV
- The video is re-encoded to Windows Media Video 8 with WMA audio.
- Re-encoding in a browser is slow: expect several times the video's length for HD footage on a laptop, and longer on a phone. Short and low-resolution clips finish much sooner.
How to convert MP4 to WMV online
- Press "Choose MP4 files" and select one or more files, or drag them onto the box. You can add files of any size your device can hold in memory.
- Adjust the settings if you need to: resolution and quality control the size of the result. The defaults suit most people.
- Press "Convert to WMV". The first audio or video conversion downloads the converter engine, about 32 MB, which your browser then keeps for next time.
- Save each WMV with its download button. Close the tab and every trace of the files is gone from memory.
Why convert MP4 to WMV?
MP4 files usually come from phone videos, YouTube uploads, social media and streaming. People convert them to WMV because WMV plays in Windows Media Player and in older PowerPoint versions without extra codecs.
In short, MP4 is good at what it was made for, and WMV is the more practical choice when the file has to play, upload or edit somewhere else. MP4 plays in every browser, phone and smart TV, while WMV does not play in browsers; plays in Windows Media Player and Films and TV.
How to convert MP4 to WMV on Windows, Mac, iPhone and Android
On Windows
Open this page in Chrome, Edge or Firefox, drag your MP4 files in from File Explorer, and press Convert. Each WMV is saved to your Downloads folder. If you prefer a desktop program, VLC can also convert MP4 to WMV: choose Media, then Convert / Save.
On a Mac
Safari, Chrome and Firefox all work. Drag the MP4 files from Finder onto the drop zone and the WMV files land in Downloads.
On iPhone and iPad
Open the page in Safari and tap Choose MP4 files. You can pick from Photos or from the Files app. The converted WMV appears in Files, in the Downloads folder; to put it in your photo library, open it there, tap Share and choose Save Video.
On Android
Open the page in Chrome, tap Choose MP4 files and pick them from Files or your gallery. The WMV is saved to the Download folder, where any file manager can find it. Keep the screen on while a long video converts, because Android may pause a tab in the background.
Best settings for MP4 to WMV
WMV is written as Windows Media Video 8 with WMA audio. The Resolution setting is the one to reach for: 1080p keeps full HD detail, 720p is plenty for phones and laptops and roughly halves the size, and 480p suits email and old devices.
The quality levels map to the H.264 CRF scale where the target uses H.264, and to fixed high-quality settings for older codecs such as MPEG-2, MPEG-4 Part 2, WMV and Theora. Re-encoding always costs a little detail, so convert from the best copy of the MP4 you have.
MP4 vs WMV: the differences
| MP4 | WMV | |
|---|---|---|
| Full name | MPEG-4 Part 14 video | Windows Media Video |
| Type | video | video |
| Created by | the Moving Picture Experts Group | Microsoft |
| First released | 2001 | 1999 |
| Compression | Lossy | Lossy |
| Usually contains | H.264 or H.265 video with AAC audio | WMV video with WMA audio in an ASF container |
| In a browser | plays in every browser, phone and smart TV | does not play in browsers; plays in Windows Media Player and Films and TV |
| Common uses | phone videos, YouTube uploads, social media and streaming | Windows Movie Maker exports and older corporate video |
| MIME type | video/mp4 | video/x-ms-wmv |
About MP4 and WMV files
What is an MP4 file?
MP4 is the most widely supported video format, and H.264 video with AAC audio inside it plays on essentially every device made in the last fifteen years.
What is a WMV file?
WMV was the default export of Windows Movie Maker, so many home videos from the 2000s are in it. Macs and iPhones never played it natively.
MP4 to WMV not working? Common problems
- The conversion is slow. Audio and container changes take seconds, but re-encoding video runs on your own processor. Lower the resolution to 720p, close other tabs, and keep the device plugged in.
- The tab stops or reloads on a very large file. Browsers limit how much memory one tab can use, around 2 GB and less on phones. Split long recordings or convert them on a computer.
- The WMV will not play on an old device. Try the other formats offered for MP4, or choose 720p, which older players handle more reliably.
Convert MP4 to WMV with ffmpeg
This converter runs ffmpeg inside your browser. If you would rather use the ffmpeg command line on your own computer, this command produces an equivalent WMV with the same kind of settings:
ffmpeg -i input.mp4 -c:v wmv2 -b:v 2500k -c:a wmav2 -b:a 192k output.wmvReplace input.mp4 with the name of your file. For a whole folder of MP4 files, run the command in a loop, or drop them all on the converter above, which processes them one after another.
MP4 to WMV converter FAQ
Will I lose quality converting MP4 to WMV?
A little. Both formats are lossy, so re-encoding compounds the loss slightly. Keep the default quality or higher and the difference is rarely noticeable.
Why is the WMV a different size from the MP4?
It depends on the settings. At the defaults, the WMV usually comes out close in size to the MP4; lower the quality for a smaller file.
Are my MP4 files uploaded anywhere?
No. The conversion runs inside this browser tab using ffmpeg compiled to WebAssembly, so your files stay on your device. You can disconnect from the internet after the page and converter engine have loaded and it still works.
Can I convert several MP4 files to WMV at once?
Yes. Select or drop as many files as you like; they are converted one after another and each gets its own download button.
How do I open a WMV file?
WMV does not play in browsers; plays in Windows Media Player and Films and TV. WMV is common for Windows Movie Maker exports and older corporate video.
Is this MP4 to WMV converter free?
Yes. There is no sign-up, no watermark and no limit on how many files you convert. The site is paid for by advertising, and because conversions run on your device there is no server cost per file.
Can I convert MP4 to WMV on my phone?
Yes. The converter works in Safari on iPhone and iPad and in Chrome on Android. Long HD videos convert more slowly on a phone than on a computer.