How to convert WMV to WebM
- Click Choose files or drop your WMV video into the box above.
- Keep the default quality, or choose a target size, resolution or frame rate.
- Click Convert and download the WebM when it is ready.
WMV vs WebM
| WMV | WebM | |
|---|---|---|
| Usual codecs | Windows Media Video 7/8/9 with WMA audio | VP8, VP9 or AV1 video with Opus or Vorbis audio |
| Plays on | Windows Media Player; not supported on Mac, iPhone, Android or in browsers | Chrome, Firefox, Edge and Android; partial support on iPhone and Mac; not accepted by many editors |
| Best for | Old Windows Movie Maker projects and archives | Video embedded in websites and screen recordings |
| Introduced | 1999 by Microsoft | 2010 by Google |
About WMV and WebM
What is WMV?
WMV was Microsoft’s main video format in the Windows XP era, produced by Windows Movie Maker and many old cameras and screen recorders. Macs, phones and browsers cannot play it, so old WMV videos are best converted to MP4.
- Plays on older Windows PCs
- No support on Mac, iPhone, Android or the web
- Obsolete
What is WebM?
WebM is an open, royalty-free video format designed for the web. Screen recorders and browsers often save clips as WebM. It is efficient, but many video editors, iPhones, smart TVs and upload forms do not handle it well, so WebM files are frequently converted to MP4.
- Royalty-free and efficient
- Plays in Chrome, Firefox and Edge
- Weak support in editors, TVs and some Apple apps
Why GlideConvert?
- Private by design. Your files are converted on your own device by your browser — they are never uploaded to a server. That keeps them private, avoids upload waits and means there is no queue.
- Fast. Images convert in a fraction of a second; video uses your device’s hardware encoder and is often simply repackaged without re-encoding.
- Free. No sign-up, no watermark. 10 images, 5 audio files or one video at a time — Pro lifts the limits and removes ads.
Frequently asked questions
Will converting WMV to WebM lose quality?
Often not at all. If the WMV file already contains video and audio that WebM supports (H.264 video and AAC audio are the most common), they are copied as-is: no quality loss, and even a large file converts in seconds. Otherwise the video is re-encoded at high quality — choose a quality level or a target file size in the options.
How long does converting WMV to WebM take?
Usually much less than the length of the video: modern browsers encode video with your device’s hardware. WMV needs a universal decoder (FFmpeg compiled to WebAssembly, a one-time ~32 MB download) which is slower — expect roughly real-time speed for HD video.
Is WMV still worth keeping?
WMV is obsolete — only Windows Media Player plays it reliably. Converting to MP4 keeps your videos watchable on any device for years to come.
Which codecs does the WebM use?
VP9 video with Opus audio when your browser can encode them (falling back to VP8), the standard WebM combination supported by Chrome, Firefox, Edge and Android.
Is there a file size limit?
On the free plan each video or audio file can be up to 500 MB and each image up to 100 MB. With Pro the limit is 4 GB per file. Because everything happens on your device, the practical limit for very large files is your device’s memory.
Are my files uploaded to a server?
No. GlideConvert runs entirely in your browser: images are processed with the browser’s built-in codecs and WebAssembly, video and audio with hardware-accelerated WebCodecs (or a WebAssembly build of FFmpeg for older formats). Nothing is sent anywhere — you can even disconnect from the internet once the page has loaded.
Does it work on iPhone, Android, Mac and Windows?
Yes. It works in any up-to-date browser — Chrome, Edge, Safari, Firefox or Samsung Internet — on phones, tablets and computers, with nothing to install. Long or 4K videos convert faster on a computer than on a phone.