LOCAL VIDEO TOOLS · WEB EMBED WEIGHT
Video to WebM Converter
Make a WebM for a page hero, a background loop or a demo clip, and keep the download small enough that visitors actually see it.
Choose a file. It stays on your device.
How to make a WebM for a web page
- 1
Add the source video, usually an MP4 export from your editor.
- 2
Convert. The picture is encoded as VP8 and the audio as Vorbis when the source has sound.
- 3
Add the file to a video tag with an MP4 fallback, then test on a phone before publishing.
Where the weight goes on a page
A hero video is usually the heaviest asset on a landing page, and it competes with the text people came to read. VP8 and VP9 store the same picture in fewer bits than H.264, which is why a WebM often lands 25 to 40 percent below the MP4 it replaces at similar quality.
This page targets a modest bitrate for VP8, so a short loop stays in the low megabytes. That is the right trade for a background clip that is muted anyway; it is the wrong tool for a full-length video someone will watch at full screen.
Ship an MP4 fallback, always
Safari supports WebM with VP8 or VP9 from version 14.1 on macOS and iOS 14.5 on iPhone and iPad. Older iPhones, some smart TVs and a long tail of in-app browsers do not, and they will show a blank rectangle with no error.
The reliable pattern is two sources in one video tag: WebM first for browsers that prefer it, MP4 second as the floor. Browsers pick the first type they can play, so nobody downloads both.
- One video tag with a WebM source first and an MP4 source second.
- A type attribute on each source, so the browser picks without downloading both.
- muted, playsinline and loop on the tag, or mobile browsers block autoplay.
Autoplay has rules you cannot encode around
Browsers block autoplay with sound. A background loop must be muted, and on iPhone it also needs playsinline or it opens full screen the moment it starts. A poster frame covers the first paint so the block is not empty while the file arrives.
Keep the loop short and cut the audio out entirely if nothing needs to hear it. A silent track still costs bytes in the container.
What leaves the file behind
Only the first video and first audio track are kept, and subtitles are dropped. Alpha transparency is not produced by this profile, so a source with an alpha channel comes out on a flat background.
The result is a WebM that plays in browsers. It will still refuse to open in QuickTime and most editors, which is expected: this format is for delivery, not for archiving.
FAQ
Is WebM smaller than MP4?
Usually, at the same visual quality, because VP8 and VP9 compress better than H.264. It is not guaranteed: a very short clip can be dominated by container overhead.
Will it play on an iPhone?
On iOS 14.5 and later, yes. Older iPhones need the MP4 fallback, which is why the video tag should list both.
Does WebM support transparency?
The format can, but the encoder used here does not write an alpha channel. Expect a flat background.
Which codec does this page use?
VP8 for video and Vorbis for audio, the pair with the widest browser support in the WebM family.
Can I use the WebM in Premiere?
Not reliably. WebM is a delivery format; convert back to MP4 for editing.
Is the conversion private?
Yes. The source file never leaves your device.