WMV to MP4 Converter
Windows Media Video was the default way to save a video on a PC for most of the 2000s. Convert those WMV files to MP4 so they play on a Mac, an iPhone, a smart TV or a web page without hunting for a plug-in.
Video Converter
or drop MP4, MOV, MKV … files here ·
Max 95 MB per file· Up to 20 files· Deleted after 30 minutes
Files are processed on our servers and deleted after 30 minutes.
Lower is better quality and a bigger file. 18 looks identical to the source, 23 is the default, 28 and above shows visible softening.
Frames per second. Keep the source rate unless a platform asks for a specific one; 15–20 fps is plenty for GIFs.
Only used for PowerPoint files and single still images: how long each slide or picture stays on screen.
Auto uses AAC for MP4/MOV and Opus for WebM. Copy keeps the original sound untouched when the new format supports it.
192 kbps is transparent for music; 128 kbps is enough for speech.
Width of the animation in pixels; height follows the aspect ratio. 480 px suits chats, 720 px or more gives a high-quality GIF but a much larger file.
GIF holds at most 256 colors. Fewer colors make a smaller file but cause banding on gradients and skin tones.
Mixes palette colors in a fine pattern to hide banding. Sierra gives the smoothest result; none gives the smallest file.
Whether the animation repeats endlessly or plays one time and stops.
Optional. Seconds (e.g. 75) or minutes:seconds (1:15). Leave empty to start at the beginning.
Optional. Same format as the start time. Leave empty to keep everything up to the end.
The converted file will be at or just under this size.
How to use this tool
- 1
Choose your WMV files
Drag them in or pick them from a folder; old .asf files are accepted too. Up to 20 at once, 95 MB each.
- 2
Keep H.264 and AAC
The page is set to Video codec H.264 and Audio codec AAC. For a low-resolution Movie Maker export there is nothing else to change.
- 3
Convert and save
Press Convert to MP4 and download each file, or take the whole batch as a ZIP.
Upload a .wmv, press Convert to MP4, and you get an H.264 video with AAC sound that plays on a Mac, an iPhone, Android, a smart TV and every browser.
Why a Mac or iPhone won't open a WMV file
WMV is not one codec but a family of Microsoft codecs stored in ASF, the Advanced Systems Format container. Microsoft licensed it widely to Windows PCs and to some DVD players, but Apple and Google never added it to their operating systems, and no browser plays it inside a web page.
That leaves a lot of video stranded: wedding slideshows made in Windows Movie Maker, training clips from a company intranet, screen recordings saved by older Windows tools, and webcam captures from laptops of that era. They still play on the PC that made them and nowhere else. VLC can open them on a Mac, but you cannot send a VLC install along with every file you share.
From Movie Maker to VC-1: a short history of WMV
1999
WMV appears
Microsoft ships Windows Media Video as part of its Windows Media platform, wrapped in ASF.
2000
Movie Maker
Windows Me introduces Windows Movie Maker, which saves finished projects as WMV.
2003
WMV 9
Windows Media 9 Series brings the codec most surviving WMV files use.
2006
VC-1 standard
WMV 9 Advanced Profile is published by SMPTE as VC-1 (SMPTE 421M) and later used on Blu-ray discs.
2017
Support ends
Windows Essentials 2012, the last Movie Maker release, loses support on January 10, 2017.
WMV
Windows Media Video
WMV is Microsoft's video format, introduced in 1999 for Windows Media Player and streaming. It uses Microsoft's own lossy video codecs inside the ASF container. It was common for older Windows recordings, presentations and downloads, but Microsoft has largely stopped developing it. macOS, iPhones, browsers and many editors do not play WMV without extra software.
- Compression
- Lossy
- Transparency
- –
- Animation
- –
- Introduced
- 1999 · Microsoft
MP4
MPEG-4 video
MP4 (MPEG-4 Part 14) is a multimedia container standardised by ISO/MPEG and based on Apple's QuickTime format. It usually holds H.264 or HEVC video with AAC audio, and can also carry subtitles, chapters and metadata. It is the most compatible video format in the world, playing on phones, browsers, TVs, game consoles and social platforms. The video inside is almost always lossy, so repeated re-encoding gradually reduces quality.
- Compression
- Lossy
- Transparency
- –
- Animation
- –
- Introduced
- 2001 · Moving Picture Experts Group (MPEG)
WMV is a Windows-only legacy: Macs, iPhones and browsers never shipped a decoder for it, so people move Movie Maker projects, old webinars and work recordings to MP4 to keep them watchable.
What the WMV to MP4 conversion changes
- new video codec
- H.264
- replaces WMA audio
- AAC
- WMV files per batch
- 20
- per file
- 95 MB
Both the picture and the sound are re-encoded, because MP4 cannot carry WMV or WMA streams. Frame size, frame rate and length stay the same unless you change Resolution, Frame rate or the trim times under Advanced settings. Many Movie Maker exports run at odd frame rates such as 15 fps; leave Frame rate on Same as source so motion keeps its original timing.
If you need the file back in Microsoft's format for an old player or a PowerPoint 2007 deck, MP4 to WMV goes the other way. For everything else, the video converter lists every target format, from MOV for Apple editing to WebM for a website.
Questions about converting old WMV files
Why does QuickTime say it cannot open my WMV?
Apple never built Windows Media decoding into macOS or iOS. QuickTime Player, Photos and iMovie read MP4 and MOV only, so a WMV either throws an error or imports as an unreadable file. An H.264 MP4 opens in all three.
Will a WMV from 2005 look better after conversion?
No converter can add detail that was never recorded. A 320 × 240 Movie Maker export stays 320 × 240; the MP4 simply plays it back without errors. Keep Resolution on Same as source, because the tool never upscales anyway.
Can I convert a WMV with DRM protection?
Files locked with Windows Media DRM, such as some old rentals or purchased music videos, are encrypted and cannot be decoded by a converter. Only unprotected WMV files, which covers home videos, screen recordings and work presentations, will convert.
What happens to the WMA soundtrack?
Windows Media Audio is decoded and re-encoded as AAC at 192 kbps, which is the audio format MP4 players expect. For a recorded lecture or webinar you can lower Audio bitrate to 128 kbps without losing clarity.
Is the MP4 smaller than the WMV?
Usually it is the same size or smaller, since H.264 is a more efficient codec than WMV 9 at the default quality. If a file needs to fit an email attachment, combine the conversion with Limit file size or see compress video to 10 MB.
Can Windows 11 still play WMV files?
Yes, Media Player in Windows 11 still decodes WMV. The problem is everywhere else: Macs, iPhones, most Android galleries and web pages, which is where MP4 is the safer copy to keep.
