Free tool

MP4 to WebM converter the video format built for web pages.

Drop MP4 videos and download WebM versions that load fast as a hero clip, a background loop or an in-app video, at the size you choose.

MP4 to WebM converter at a glance

content.win converts and compresses video for free, several files at once, and never adds a watermark. You can name an exact size in MB and get a file that fits.

Works with
MP4, MOV, WebM and MKV.
Comes back as
MP4, MOV, WebM or MKV, at a quality preset or an exact target size in MB.
Runs
In your browser.
Limits
Up to 10 videos at once, in a browser that can play them. Free space on the device is the only other limit.
Price
Free. No account, no watermark.

How to convert MP4 to WebM

  1. Drop the MP4 videos in. One or several.
  2. Pick a quality or a target size. Balanced is right for a page; type a size in MB if the site builder has a ceiling.
  3. Download the WebMs. Named after the originals, ready for a video tag.

WebM on a web page

Smaller
WebM at the same look is usually smaller than an MP4, which matters for a clip that plays on every visit.
Every browser
Chrome, Firefox, Edge, Safari and phone browsers play WebM. Keep the MP4 as a fallback source in the video tag and nothing is left out.
Background loops
Cap the resolution at 720p or 1080p and pick Balanced; a background clip does not need more.

Questions people ask

Does Safari play WebM?

Current Safari does. Keeping the MP4 as a second source in the video tag covers older versions.

Is WebM smaller than MP4?

Usually, at the same visual quality. The tool shows both sizes.

Can I set an exact size?

Yes. Pick Target size and type the MB the builder or CMS allows.

Can I convert several at once?

Yes, up to ten in one drop.