WMV to MP4 converter

Windows Media files from old Movie Maker projects or screen capture tools do not play on Macs, iPhones or the web.

Drop a WMV file hereThe converter loads in your browser.

What happens to your WMV

WMV/VC-1 video is decoded and re-encoded to H.264; WMA audio becomes AAC.

Tip: WMV Screen (MSS2) and some DRM-protected WMV files cannot be decoded by any open tool, including this one.

How to convert WMV to MP4

  1. Drop your WMV file on the box above, or tap it to pick one. The engine (about 31 MB) loads once per visit.
  2. The converter reads the file's streams and shows which codecs are inside.
  3. Keep the defaults, or pick a quality and resolution.
  4. Press the button, wait for the progress bar, then download your MP4.

Prefer the command line?

This is the FFmpeg command the converter runs for a typical WMV (wmv3 + wmav2). Paste it into a terminal with FFmpeg installed for batch jobs or files too big for a browser tab:

ffmpeg -y -i input.wmv -map 0:v:0 -map "0:a:0?" -sn -dn -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" -c:v libx264 -preset veryfast -crf 23 -pix_fmt yuv420p -movflags +faststart -c:a aac -b:a 160k output.mp4

This re-encodes, so expect it to take a while on long files. Your own file may contain different codecs; the converter above detects them and adapts. For other jobs, ask the FFmpeg command helper.

Questions

Can it convert protected WMV?

No. DRM-protected Windows Media files are encrypted and cannot be converted.

Is my WMV file uploaded?

No. The WMV is read from your device by FFmpeg running as WebAssembly in the page, and the MP4 is written back to your device. No server ever receives it.

Is there a size limit for WMV to MP4?

We set none. The practical limit is browser memory: roughly 2 GB of output on a computer, and much less on phones.