MP4 to WebM
Turn MP4 videos into WebM files for websites, web apps and browser games.
or drop it here · up to 50 MB, free
Bigger files? Pro converts files up to 500 MBOver the free limits: you can unlock the download from €1.99.
Working on it…
Your file is ready
Free · No sign-up · No watermark · Your files never leave your device
MP4 to WebM in 3 steps
- Select your MP4 video, or drop it on the box.
- Click Convert to WebM.
- Download the WebM when the progress bar is full.
When WebM is the better choice
WebM is the open video format made for the web. Its VP9 video is royalty-free, often smaller than H.264 at the same quality, and plays in Chrome, Edge, Firefox and Safari. Developers use it for background videos and animations, and some platforms and game engines ask for WebM specifically.
The tool re-encodes the video as VP9 (or VP8 where the browser cannot write VP9) and the sound as Opus, keeping the resolution and frame rate. If you need an animation with a transparent background, start from a source that has one: an MP4 never carries transparency, so the WebM will not either.
Frequently asked questions
How do I convert MP4 to WebM for free?
Select the MP4 file and click Convert to WebM. The video is re-encoded in your browser and the WebM downloads when it is ready. There is no sign-up and no watermark, and MOV files from a phone work too.
Is WebM smaller than MP4?
Often, yes. VP9 usually needs less data than H.264 for the same picture, so a WebM can be noticeably smaller. The exact difference depends on the video: busy scenes with lots of movement gain less than calm ones.
Which codec does the WebM use?
VP9 for the video and Opus for the sound, the usual pair for modern WebM. If your browser cannot encode VP9, VP8 is used instead, which every browser that plays WebM also supports.
Will the WebM play on an iPhone?
In Safari on iPhone and Mac, recent versions play WebM with VP9. Some apps and older devices still do not, so if the video is meant for people rather than a website, MP4 remains the safer choice.
Which browsers can do this?
Converting uses the video encoder built into your browser. Chrome and Edge on a computer or Android phone work best. Safari 17 or later and recent Firefox versions also work, but they are slower with large videos. If your browser cannot do it, the page tells you before you start.
Is my video uploaded to a server?
No. The video is processed by your own browser on your device, so it is never sent to us or stored anywhere. That also means there is no upload to wait for, which saves a lot of time with large videos.