Step 1: Provide your WMV files using the button above or by toss and let go.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Fetch your converted MP4 files.
WMV to MP4 Conversion FAQ
How do I convert WMV to MP4 without re-encoding the video stream?
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There is no stream-copy switch on this page. A few pairs copy a compatible video stream into the MP4 container without re-encoding it, MKV to MP4 among them, which is quick and loses no quality. Most pairs re-encode the video. WMV carries Microsoft’s own VC-1 or WMV3 video with WMA audio — codecs almost nothing outside Windows decodes natively. Almost every MP4 in the wild is H.264 video with AAC audio; the container also legally holds HEVC, AV1 and VP9.
My WMV footage shows comb lines on movement — will that carry into the MP4?
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Yes. WMV content is often interlaced, because the format comes from the broadcast and DVD era, and this converter has no deinterlace option, so the combing carries into the MP4. If it matters, deinterlace the WMV first in a desktop tool such as HandBrake or ffmpeg (the yadif filter). WMV is Windows Media Video, Microsoft’s ASF-based format from the Windows XP era.
Can I add selectable subtitles once the file is MP4?
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Yes. WMV has no usable soft-subtitle track, so subtitles for WMV content had to be burned into the picture or shipped as a separate sidecar file. MP4 carries subtitles as their own selectable stream, so after conversion you can attach an SRT track the viewer can switch on, switch off or restyle.
Why does my WMV file fail to convert to MP4?
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Almost always DRM. Some WMV files are encrypted at the bitstream level by the store or software that issued them, and an encrypted stream cannot be decoded by us or by anything else without the licence key. Files you recorded, exported or downloaded unprotected convert normally; a licensed purchase will not, and no converter can honestly promise otherwise. WMV is effectively a dead end: macOS, iOS, Android and every browser need third-party decoders, and some WMV files carry DRM that cannot be converted at all.
Will the MP4 play in a browser when the WMV would not?
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Yes, and that is usually the whole reason for the conversion. A WMV embedded in a web page either shows a broken player or forces a download, because browsers ship no decoder for it. MP4 plays inline through the native HTML5 video element with no plugin and no external application. MP4 is the safest possible delivery target — every phone, browser, console, editor and Smart TV built in the last decade plays it without extra software.
Is it worth converting old WMV recordings to MP4 at all?
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For anything you intend to keep, yes. WMV belongs to an earlier generation of video tooling and the software that reads it is steadily disappearing from phones, browsers and operating systems. Moving the footage to MP4 now, while a clean decoder still exists, is the difference between an archive you can open in ten years and one you cannot.
Will multi-track audio survive WMV to MP4 conversion?
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Usually not. Most conversions keep one audio track, the one with the most channels (normally the main mix), re-encoded for the MP4 container, so commentary and alternate-language tracks are dropped. AVI, WMV, MPEG, FLV, VOB and M4V to MKV keep every track, and so does MP4 to MOV. To keep a different track, remux the WMV with that track first (VLC or ffmpeg can do this), then convert it. MP4 is ISO/IEC 14496-14, standardised in 2001 and derived from the same QuickTime box layout MOV uses.
Are subtitle tracks preserved when converting WMV to MP4?
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On some pairs. MP4 to MOV keeps every text subtitle track. AVI, WMV, MPEG, FLV, VOB and M4V to MKV keep every subtitle track: text subtitles are copied or converted to SRT, and picture-based subtitles such as DVD or Blu-ray ones are copied as they are. MP4, MOV and WebM to MKV keep only the first subtitle track (as ASS), and MP4 to WebM keeps the first one as WebVTT. Other pairs, including MKV to MP4 or MOV and WebM to MP4, drop subtitle tracks, and the converter does not burn them into the picture. Subtitles that are already burned in stay, because they are part of the video frames.
What about MKV attachments (fonts, cover art) when going WMV to MP4?
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MKV is the only mainstream container that stores arbitrary attached files (TTF fonts for ASS subs, JPG cover art, fan-translated PDF inserts). Going from WMV to MP4 drops these attachments when MP4 is not MKV — the elementary streams convert, but the attached payload stays in the source. Keep WMV as a backup if you depend on attached fonts.
Which codec does the MP4 output use by default?
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It depends on the MP4 container. MP4, MOV and MKV output use H.264, which plays on practically every phone, browser and TV. WebM output uses VP9. AVI, WMV and MPEG output use the older codecs those formats were designed for. MP4 only supports one widely-honoured subtitle format (mov_text), and multi-track audio is unreliable outside desktop players.
How does HDR (HDR10, Dolby Vision) survive WMV to MP4?
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There is no HDR processing or tone mapping. When the video stream is copied (MKV to MP4 or MOV with the default settings), HDR10 passes through as it is. When the video is re-encoded, the HDR10 mastering metadata is dropped and Dolby Vision or HDR10+ data is not kept, and with a Quality, Resolution or Frame Rate setting some pairs also reduce the video to 8-bit colour, so an HDR WMV can look washed out in the MP4.
