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Convert MP4 to WebM

Choose a quality, convert your MP4, and download the finished WebM video.

InputMP4, WebM, MOV and M4V videoOutputWEBM

MP4Drop an MP4 hereor click to choose a video.

WebM exists to make video cheap to serve on the open web: it is royalty-free, and VP9 typically delivers the same visual quality as H.264 in noticeably fewer bytes. Converting an MP4 to WebM here lets you choose between VP9 and the older VP8, set the quality, and preview the result locally before you publish it.

VP9 or VP8

VP9 is the one to use in almost every case: at equal quality it produces substantially smaller files than VP8 or H.264, and every current browser decodes it. VP8 is older, encodes faster and is supported by a slightly wider range of very old software, which is essentially its only remaining argument. The trade-off with VP9 is encoding time — it is a heavier codec, and a long high-resolution clip takes real minutes on a laptop. That is a one-off cost paid against every future download.

Where WebM is the right answer

Serving video from your own site is the clear case: smaller files mean faster starts and less bandwidth, and every browser plays them. WebM is also the format to reach for when you need transparency, since alpha-capable WebM does something MP4 simply cannot. Where it is the wrong answer is anywhere the file will be handed to a person or an app rather than a browser — messaging, TVs, older phones, and several desktop editors either refuse WebM or handle it awkwardly. Keep an MP4 for distribution and use WebM for delivery.

Questions, answered

Should I choose VP9 or VP8?

VP9 unless you have a specific reason not to. It gives clearly smaller files at the same quality and is supported by every current browser. VP8 only encodes faster.

Is WebM smaller than MP4?

Usually yes at the same visual quality — often 20–40% smaller with VP9. The saving depends on the content: it is largest on clean, low-motion footage.

Will WebM play everywhere?

In browsers, yes. Outside them it is far patchier: some TVs, older phones, messaging apps and desktop editors will not open it. Keep an MP4 for anything you send to people.

Why is the conversion slow?

VP9 is computationally heavy, and the encode runs on your own device rather than a server. Long or high-resolution clips take minutes; the payoff is a smaller file forever after.

Can WebM have a transparent background?

Yes — WebM supports an alpha channel, which MP4 does not. That is why transparent video for the web is delivered as WebM.

Convert MP4 to WebM

VP9 or VP8

Where WebM is the right answer

Questions, answered

Useful next steps