Convert WMV to MP4

How it works

1. 1

   Add your WMV file

   Drop, pick, or paste it. It stays on your device.

2. 2

   Convert

   We re-encode it to MP4 right here in your browser.

3. 3

   Download

   Save the MP4 file.

A format that never left its home platform

WMV came out of Windows Media, and Microsoft built it for a world where the video was going to be watched on a Windows PC in Windows Media Player. Within those walls it worked fine. Step outside them, onto a Mac, an iPhone, or a website, and support ranges from grudging to nonexistent.

The codec inside is usually Windows Media Video, which is not something MP4 can carry, so this is a genuine re-encode rather than a rewrap. The video has to be decoded and compressed again as H.264, which takes real time and costs a generation of quality.

Most WMV files that people still have are old: exported from an early version of Windows Movie Maker, or downloaded when that was how video came. Converting to MP4 makes them portable and future-proof, which is worth doing before the format becomes any more obscure than it already is.

Why nothing uploads

Other tools send your video to their servers, which costs them money per file, so they add watermarks, cap file sizes, and make you sign up. This tool does the work right here in your browser using your own device. Your file is never uploaded, so there is no wait, no watermark, no size limit, and no account.

Questions

Why will my Mac not play a WMV?

Because Windows Media Video is a Microsoft codec and macOS has never shipped support for it. Converting to MP4 is the practical fix.

Can this be remuxed instead?

No. The Windows Media codec inside cannot be carried by an MP4, so the video genuinely has to be re-encoded.

Will it look worse?

Slightly, in principle, since re-encoding always costs something. In practice the settings used here make it very hard to see, and the original was rarely pristine to begin with.

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