WebM for HTML

Drag your video here

Or

Everything you need for an HTML5 video element: a WebM source, an MP4 fallback, and the markup to use them. Render both formats at once with the + button.

How to use the WebM for HTML

  1. Add your video filesDrag them onto the drop zone above, or click to browse. Add as many as you like — they stay on your computer.
  2. Tune the settingsPick WebM or MP4 — hover another format and press + to render several at once. Set quality, frame rate and scale. Leave Transparency on to keep any alpha channel.
  3. Convert and downloadClick Convert. Each finished WebM and MP4 file gets its own download button, or grab everything with Download all.

HTML video markup

List WebM first so browsers that support it download the smaller file, and MP4 second as the fallback: <video autoplay loop muted playsinline poster="poster.jpg"><source src="clip.webm" type="video/webm"><source src="clip.mp4" type="video/mp4"></video>.

autoplay needs muted to work, playsinline stops iOS going fullscreen, and a poster image shows instantly while the video loads.

Frequently asked questions

What is the MIME type for WebM?

video/webm. For MP4 it is video/mp4.

Why is my WebM not autoplaying?

Browsers block autoplay with sound. Add the muted attribute (and playsinline for iOS).

Do I need both WebM and MP4?

It is best practice: WebM for size, MP4 so every device can play it.

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