MP4 to WebM Converter

Convert MP4 to WebM for smaller, web-native video that streams fast - all processed in your browser.

About this converter

WebM is the open, royalty-free video format designed for the web. Its VP9 codec usually produces a smaller file than H.264 at the same quality, which means faster-loading pages and less bandwidth - ideal for background videos and self-hosted clips on a website.

Converting MP4 to WebM re-encodes the video from H.264 to VP9. It is the right move for web delivery, though note that WebM is not ideal for video editors or older Apple devices - keep an MP4 for those.

MP4 to WebM: good to know

WebM (VP9) is typically smaller than the equivalent H.264 MP4 - good for web performance.
Best for websites and HTML5 video, not for editing software or older iOS devices.
A modern best practice is to offer both a WebM and an MP4 source in your video tag.

How it works

Drop your file(s) in the box above (or click to browse).
Make sure WebM is selected as the output.
Click Convert, then Download your file.

Frequently asked questions

How do I convert MP4 to WebM?

Drop your MP4 above, choose WebM as the output, and click Convert, then Download. It all runs locally.

Why convert MP4 to WebM?

WebM's VP9 codec is open and usually smaller than H.264 at the same quality, so it loads faster on web pages and saves bandwidth.

Will the WebM be smaller than the MP4?

Often yes - VP9 generally compresses more efficiently than H.264, so the WebM can be noticeably smaller at similar quality.

Should I use WebM for everything?

No. WebM is great for the web but not well supported by editors and older Apple devices. Keep an MP4 for editing and broad device playback.

Is it private?

Yes. Encoding happens in your browser via WebAssembly, so your video never leaves your device.

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