Last updated: July 2026
Turn a normal clip into a WebM with a genuine VP9 alpha channel — the background isn't a colour to key out, it's simply not there. Upload a video of a person and download a transparent WebM that plays over any background. Free, no sign-up, no watermark.
Remove my video background now →A transparent WebM stores an alpha channel: every pixel has a see-through value, so the subject stays fully opaque while the background is literally empty. That's different from a green screen, where the background is a real green colour you still have to remove. VideoBGNinja produces the alpha for you, no keying required.
For the full rundown of where alpha WebM plays and how to use it, see the transparent video guide — this page is the quick how-to for the conversion itself.
Chrome, Edge and Firefox play VP9 alpha natively in a <video> tag, OBS accepts it as a media source for stream overlays, and editors like DaVinci Resolve, Premiere Pro and After Effects import it directly. For an app that can't read alpha, use the green-screen MP4 that comes with every job instead.
<video> with transparencyThe tool is tuned for short clips: up to 1 GB and 60 seconds per upload, processed at up to 1280px. Longer material? Trim it into parts first — that keeps processing fast and free for everyone. It's trained on people, so a human subject is what it does best.
The transparent file you download is a WebM containing VP9 video in yuva420p — the "a" is the alpha channel, and it's what makes the transparency real rather than a colour that gets keyed out later. It's encoded at CRF 32 with no bitrate cap, which for a matted subject on nothing is a good quality-per-byte trade: most of the frame is empty, and empty compresses to almost nothing. If your clip has audio it travels along as Opus at 128 kbps.
The obvious question is why this isn't just an MP4. The answer is that the H.264 video inside a normal MP4 has no usable alpha channel — the spec has provisions almost nothing implements, so in practice an MP4 cannot carry transparency that any player or editor will honour. The formats that can are all more awkward:
Which leaves VP9-in-WebM as the one option that plays natively in every current browser, keeps a real alpha channel, and produces a file you can actually put on a website. That's why it's the default here rather than a niche export.
Transparency is easy to lose by accident, and the failure is quiet: the file plays fine, it just has a black box around your subject. Two checks worth knowing.
Check the file itself. If you have ffmpeg installed, ffprobe -v error -select_streams v:0 -show_entries stream=pix_fmt -of csv=p=0 yourfile.webm should print yuva420p. If it prints yuv420p without the "a", the alpha is gone.
Check it in place. Put the video on a page over something loud — a bright coloured block, not white, because black-on-white and no-alpha-on-white look identical at a glance:
<div style="background:#e0218a">
<video src="you.webm" autoplay muted loop playsinline></video>
</div>Pink should show through around your shoulders. If you see a black rectangle instead, the alpha was stripped somewhere.
The usual culprit is a re-encode. Anything that passes the file through a converter, a "compress my video" web tool, an upload that transcodes, or an editor export that defaults to H.264 will flatten alpha to black without warning you. Keep the original WebM as your master, and when you must re-encode, name the pixel format explicitly: -c:v libvpx-vp9 -pix_fmt yuva420p. Note also that transparency is a file property, not a platform one — upload a transparent WebM to YouTube or Instagram and it gets flattened on their side, because their players composite everything onto opaque video.
A WebM video that carries a real alpha (transparency) channel, so the background is empty rather than a solid colour. It drops onto any background without keying.
Chrome, Edge and Firefox play it natively, OBS reads it as a media source, and Resolve, Premiere and After Effects import it. Use the green-screen MP4 for apps that don't.
Yes. Your original audio is kept in the WebM (Opus) and in the green-screen MP4 (AAC).
Up to 1 GB and 60 seconds per clip, processed at up to 1280px.