Convert MP4 to WebM

How it works

1. 1

   Add your MP4 file

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

2. 2

   Convert

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

3. 3

   Download

   Save the WEBM file.

WebM is for serving video, not for sending it

This is the one conversion on the site that is usually a deliberate technical decision rather than a workaround. Nobody converts to WebM because something refused to open their MP4. They do it because they are putting video on a page and they want it to be smaller.

VP9, the codec WebM usually carries, is meaningfully more efficient than the H.264 inside a typical MP4: the same visual quality lands in a noticeably smaller file, which is bandwidth you do not pay for and load time your visitors do not wait through. It is also royalty-free, which is why the open web standardized on it.

The catch is the flip side of the same coin. Do not convert to WebM for a file you plan to email, message, or hand to somebody, because their phone or their editor may well refuse it. WebM belongs in a video tag on a page you control. For everything else, MP4 remains the answer.

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

Is WebM actually smaller?

Yes, usually. VP9 typically reaches the same quality as H.264 in a smaller file, which is the main reason to use it for web delivery.

Should I send someone a WebM?

Better not to. Support outside browsers is patchy, and Apple hardware in particular is unenthusiastic. Send an MP4 and serve a WebM.

Do I still need an MP4 fallback on my site?

Far less than you used to. Every current browser handles WebM, though keeping an MP4 alongside it is still the cautious choice for older devices.

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