Convert Video to WebM — Free MP4 to WebM
Convert video to WebM for smaller, faster-loading web pages.
Drop a file here
or click to choose a file
Runs on your device Your file is processed by your own browser and is never uploaded to a server.
Short answer
Video can be converted to WebM in a browser without uploading. WebM pairs the royalty-free VP8 or VP9 video codec with Vorbis or Opus audio and is designed for the web, where it usually produces smaller files than H.264 at the same visual quality. VP8 encodes several times faster than VP9 in a browser, which makes it the practical default.
At a glance
| Accepts | MP4, MOV, MKV, AVI |
|---|---|
| Produces | WebM (VP8 / Vorbis or VP9 / Opus) |
| Processing | In your browser |
| Price | Free, no limits |
| Account | Not required |
WebM exists to be served over the web: it is royalty-free, every modern browser decodes it natively, and at equivalent quality it is typically smaller than H.264. For background videos, hero loops and embedded clips, that size difference translates directly into faster page loads.
VP9 compresses better than VP8, but in a browser-based encoder it runs roughly an order of magnitude slower. Start with VP8; reach for VP9 only for short clips where the last few percent of file size genuinely matters.
How to use it
- 1
Add the video
Drop in an MP4, MOV, MKV or other common file.
- 2
Choose a codec
VP8 is fast and reliable. VP9 is smaller but much slower to encode.
- 3
Convert
The video is re-encoded to WebM on your device.
- 4
Download the WebM
Save it and serve it from your site.
Frequently asked questions
Should I use VP8 or VP9?
VP8 for anything longer than a few seconds, because browser-based VP9 encoding is dramatically slower. VP9 produces smaller files and is worth the wait only for short clips.
Do all browsers play WebM?
All current versions of Chrome, Firefox, Edge and Safari decode WebM. Support outside browsers — in editors, on TVs and on some phones — is much weaker.
Why is WebM encoding so slow here?
VP8 and VP9 are computationally heavier than H.264, and the encoder runs single-threaded inside a browser sandbox. Shorter clips and lower resolutions help considerably.
Is WebM better than MP4?
For serving video on a web page, usually yes — smaller files and no licensing concerns. For sharing files with people or importing into editing software, MP4 remains the safer choice.