Convert MP4 to transparent WebM
Remove a solid-color background and export alpha WebM. Check the result against your intended page background.
Source: a green-screen keying sample
Synthetic sample · MP4 · 4 seconds · static subject
The sample removes its green background and selects WebM. Preview the exported video on a different background to check transparency in your browser.
Try this sampleThe problem
Transparent video on the web is still fragmented. MP4 is broadly supported but does not carry alpha in normal browser playback; GIF supports transparency but only with hard edges.
Alpha WebM can fit a native video element, but transparency must survive both export and playback. A checkerboard preview before export is only the first check.
For short AI-generated green-screen clips, the fastest path is usually to key and encode directly in the browser.
The browser workflow
EasyLottie decodes MP4/MOV/WebM locally, applies a WebGL chroma key, and records VP8 WebM with alpha when the browser supports it.
The tool checks WebM recording support and disables known unsupported paths, including Firefox. The exported video still needs a playback check in the browsers you plan to support.
If WebM is not a fit, the same keyed result can be exported as Lottie ZIP, transparent GIF, or PNG sequence.
Complete the task
Use a Chromium browser
Start with a current Chromium-based browser. The tool checks the required recording APIs and disables known unsupported export paths; test alpha playback on the browsers your audience uses.
Drop the MP4 or MOV
Upload a short green-screen or solid-background clip.
Pull the key
Sample the background and tune tolerance, softness, despill, and choke.
Choose WebM
Select transparent WebM output and set size, fps, and quality.
Download and test
Export the WebM and test it over the intended page background.
Common use cases
Landing page loops
Use alpha WebM for smooth transparent hero or feature clips in Chromium-heavy audiences.
AI video overlays
Turn a generated subject-on-green clip into an overlay that sits on top of product UI.
Prototype assets
Create transparent motion clips for experiments before committing to a production animation pipeline.
Frequently asked questions
Why not transparent MP4?
Standard browser MP4 playback does not reliably preserve alpha. WebM with VP8 alpha is the practical browser format for Chromium.
Why is WebM disabled in Firefox?
This tool disables its VP8 alpha recording path in Firefox because that workflow can lose transparency. Choose another output or use a supported Chromium-based browser.
Can Safari play transparent WebM?
Safari support is not reliable for this workflow. For Safari-heavy audiences, use PNG sequence or evaluate an alternate delivery path.
Is anything uploaded?
No. Decode, keying, and encoding run locally in the browser.
Can I export Lottie from the same file?
Yes. You can switch output to Lottie ZIP, transparent GIF, or PNG sequence.
Related guides
Remove a video background
AI video to transparent background
Put a transparent video on your website
Compare GIF, WebM, and Lottie output
Play an exported Lottie ZIP on your website
Green screen to transparent GIF
Video to Lottie converter
Ready to try it?
Free to use, no signup. Files are processed locally by default.