WMV to MP4 Converter
Convert WMV (Windows Media Video) files to MP4 that plays on iPhones, Macs, TVs and in any browser, with full control over quality, bitrate, frame rate, resolution and audio.
Also: MKV to MP4 converter · AVI to MP4 converter · MOV to MP4 converter · WebM to MP4 converter · FLV to MP4 converter · TS to MP4 converter · MPEG to MP4 converter · 3GP to MP4 converter · M4V to MP4 converter · MOD to MP4 converter · VOB to MP4 converter · MTS to MP4 converter · OGV to MP4 converter · RM/RMVB to MP4 converter · MXF to MP4 converter · MP4 compressor · Video to MP3 extractor · MP4 to GIF converter · Video format converter
Click to choose a video, or drag and drop
Choose a WMV or ASF file — MKV, AVI, MOV, WebM, TS, FLV and most other formats are accepted too. Stays on your device.
Your video is converted entirely in your browser and is never uploaded. The converter engine (ffmpeg, ~32 MB) is downloaded once and cached by your browser.
Frequently asked questions
Why convert WMV to MP4?
WMV is a Windows Media format from the 2000s. iPhones, Macs, Android phones, smart TVs and browsers do not play it, and many video editors dislike it. MP4 with H.264 plays almost everywhere. WMV uses its own codecs, so the video is always re-encoded rather than just repackaged.
Will converting WMV to MP4 lose quality?
A re-encode is always slightly lossy, but WMV files are usually low resolution and heavily compressed, so a CRF of 18 to 23 keeps the result visually the same. The MP4 is often smaller than the WMV. Avoid enlarging the resolution, because it does not add detail.
Can it convert a protected (DRM) WMV file?
No. WMV files protected with Windows Media DRM, such as some old downloads and rentals, are encrypted and cannot be read by any converter without the license. An ordinary unprotected WMV converts normally.
Is my video uploaded anywhere?
No. The conversion runs entirely in your browser using ffmpeg compiled to WebAssembly. Your video never leaves your device. Only the converter engine itself (about 32 MB) is downloaded, once, and cached by your browser.
What is Fast remux and when should I use it?
A WMV file is just a container. If the video inside is H.264 (or another format MP4 supports) and the audio is AAC, MP3 or AC-3, those streams can be moved into an MP4 container as they are. That takes seconds and loses no quality at all. The tool checks your file and picks this automatically when it is possible.
What do CRF and bitrate mean?
CRF (constant quality) lets the encoder spend as many bits as each scene needs: lower numbers mean better quality and bigger files, around 18 looks near-lossless, 23 is the default and 28 is noticeably smaller. A target bitrate instead aims for a fixed number of kilobits per second, which gives a predictable file size but variable quality.
Why is re-encoding slow, and is there a size limit?
Re-encoding runs on a single CPU thread inside the browser (H.264 only), so it is usually near real-time speed or slower for HD. The finished MP4 also has to fit in browser memory, which in practice limits output to roughly 1 to 2 GB. For a long movie, use Fast remux, trim it, or copy the generated command and run it with ffmpeg on your own computer.
What happens to subtitles?
MP4 supports text subtitles only. SRT, ASS/SSA and WebVTT tracks are converted to the MP4 text format, and you can also save a track as a separate .srt file. Picture-based subtitles from Blu-ray or DVD (PGS, VobSub) cannot be converted.