Does converting WMV to MP4 reduce quality?

Yes, slightly, because this is a re-encode to H.264 rather than a remux. CRF 23 stays close for ordinary viewing. Keep the WMV if it is the only master. The MP4 exists so Mac, iPhone, and websites can play a copy without Windows Media Player.

Why won't QuickTime or iPhone open my WMV?

They do not include Windows Media decoders. The file can be healthy and still fail. Re-encoding to H.264 in MP4 is the compatibility fix. Renaming .wmv to .mp4 does not add those decoders and will fail in a more confusing way.

Is this a remux or a re-encode?

A re-encode. WMV and WMA are not the pair Safari and iPhone expect inside MP4. This tool writes libx264 video and AAC audio with fast-start. Stream copy would produce an MP4 that still needs Windows codecs, which defeats the conversion.

Will this work on iPhone or Android?

The converter runs in Safari and Chrome. Re-encoding is heavy, so a long training WMV can exhaust phone memory. Prefer a computer for anything beyond a short clip..

Can I convert several WMV files at once?

Not currently. Each encode keeps frames in memory. Convert one, download the MP4, then drop the next. After the engine loads once, later files skip that download. A folder of meeting recordings is still one WMV file dropped each time.

Is it legal to convert WMV to MP4?

Re-encoding a recording you made or a training file you have permission to use is the intended case. Re-encoding a commercial Windows Media title you do not have rights to does not become lawful as MP4. Videozify never sees the file.

WMV → MP4

WMV to MP4 Converter

Drop a file here

Click to browse, or paste a file from the clipboard.

Choose file

A WMV to MP4 converter re-encodes a Windows Media video into H.264 MP4 that Mac, iPhone, and the web will actually play. Drop the file, convert, and download an MP4 you can send without asking anyone to install Windows Media Player.

How to convert WMV to MP4

Drop your WMV file onto the box above, or click Browse to choose it from disk.
Confirm the selected clip is the one you want; this conversion re-encodes to H.264.
Press Convert and wait until the progress bar reaches one hundred percent.
Download the MP4 when it appears; the file saves only to this device.

Why convert WMV to MP4?

WMV is a video format Microsoft built around Windows Media Player, Movie Maker, Outlook attachments, and a decade of corporate training exports. Macs never treated it as native. iPhone still does not. A file that plays on the office PC is a brick on the laptop in the other room. Converting is how those clips leave the Windows ghetto without dragging a codec pack along.

This is a re-encode, not a remux. WMV video (often WMV9 / VC-1) and Windows Media audio are not what MP4-on-Safari expects. Copying streams would produce a file that still fails. The preset decodes the WMV and writes libx264 at CRF 23 with ultrafast, AAC at 128kbps, and fast-start so the MP4 can begin playing before it fully downloads.

Corporate and school archives are the usual pile: a 2011 induction video, a webinar someone "saved as WMV," a wedding clip from an old Windows laptop. Quality of those sources is already limited. A second H.264 pass at CRF 23 is usually less of a problem than "nobody can open this." Keep the WMV if it is the only master from a capture card you no longer own.

Use this when a Mac user cannot play the attachment, when an LMS rejects .wmv, or when you want the clip in the same MP4 pile as phone footage. If you only needed the narrator, extract audio from the video instead of paying for a full re-encode.

If the MP4 is still too large for Outlook, compress the video after converting. If you only needed one slide from a long recording, trim the video instead of sending the whole hour.

WMV vs MP4: what's the difference?

	WMV	MP4
Extension	.wmv	.mp4
Type	Windows Media video	MPEG-4 container
Typical size (4 min)	30–80 MB	Often similar after H.264
Compression	WMV / VC-1 + WMA	H.264 + AAC
Quality	Source Windows encode	Re-encoded (CRF 23)
Device support	Windows Media Player first	Mac, phones, web, editors

WMV is a Windows Media video format that Microsoft built for Windows Media Player, which Mac and iPhone still will not play natively.

Will the MP4 look worse than the WMV?

A little. Decoding VC-1 or WMV9 and encoding H.264 is a second lossy pass. CRF 23 is a standard web-video target. Ultrafast keeps the browser encode from lasting forever, at the cost of a slightly less efficient file. You may not notice on a training video. You might on a clean desktop capture.

Audio becomes AAC at 128kbps. Speech-heavy WMV survives this. Music beds take a small extra hit. There is no quality dropdown on this page; the preset is fixed so the result is a predictable, playable MP4.

If you need a smaller file after it plays on the Mac, compress the video as a second step. Stacking mystery bitrates into this first pass would make the page less honest about what the engine actually does.

Why won't my Mac play a WMV file?

Apple never shipped Windows Media codecs in QuickTime the way Windows shipped them in Media Player. Third-party players can decode WMV. The Photos app, Mail preview, and iMovie usually will not. Colleagues who "just double-click" on a Mac see an error, not a video.

iPhone is stricter. There is no WMV decoder in iOS video. AirDropping the WMV does nothing useful. AirDropping an H.264 MP4 does. That is the entire product reason for this page.

Some files named .wmv are ASF containers with odd DRM leftover from old Windows Media licences. DRM-wrapped files will not decode here. Unprotected Movie Maker and Screen Recorder exports generally will. If the job fails immediately, the file may be protected or using a codec this wasm build cannot read.

Frequently asked questions

Does converting WMV to MP4 reduce quality?: Yes, slightly, because this is a re-encode to H.264 rather than a remux. CRF 23 stays close for ordinary viewing. Keep the WMV if it is the only master. The MP4 exists so Mac, iPhone, and websites can play a copy without Windows Media Player.
Why won't QuickTime or iPhone open my WMV?: They do not include Windows Media decoders. The file can be healthy and still fail. Re-encoding to H.264 in MP4 is the compatibility fix. Renaming .wmv to .mp4 does not add those decoders and will fail in a more confusing way.
Is this a remux or a re-encode?: A re-encode. WMV and WMA are not the pair Safari and iPhone expect inside MP4. This tool writes libx264 video and AAC audio with fast-start. Stream copy would produce an MP4 that still needs Windows codecs, which defeats the conversion.
Will this work on iPhone or Android?: The converter runs in Safari and Chrome. Re-encoding is heavy, so a long training WMV can exhaust phone memory. Prefer a computer for anything beyond a short clip..
Can I convert several WMV files at once?: Not currently. Each encode keeps frames in memory. Convert one, download the MP4, then drop the next. After the engine loads once, later files skip that download. A folder of meeting recordings is still one WMV file dropped each time.
Is it legal to convert WMV to MP4?: Re-encoding a recording you made or a training file you have permission to use is the intended case. Re-encoding a commercial Windows Media title you do not have rights to does not become lawful as MP4. Videozify never sees the file.