Comment ça marche
- 1Upload MP4, MOV, WEBM, or MKV
- 2Pick WebM (alpha for the web) or MOV (ProRes 4444 for editors)
- 3Keep existing alpha, or chroma-key green / blue / white / black / custom
- 4Preview on a checkerboard (WebM) and download
Outil en ligne gratuit
WebM VP9 alpha ou ProRes 4444
WebM VP9 alpha ou ProRes 4444
WebM VP9 alpha ou ProRes 4444
Le MP4 H.264 n’a pas d’alpha. WebM VP9+alpha pour Chrome/Firefox ; ProRes MOV pour le montage.
Prêt — déposez un fichier ci-dessous.
Browser-playable overlay with a real alpha channel. Requires -auto-alt-ref 0.
Editing format with alpha for Premiere / Final Cut. May not preview in the browser.
H.264 sources have no alpha — key out green/white/black to create one.
Standard H.264 MP4 has no alpha plane. The pixels are opaque. True transparency needs a format that stores alpha, such as VP9 WebM or ProRes 4444.
Choose that key color. Similarity controls how close a pixel must be; blend softens the edge.
Set background key to “Keep existing alpha” so we re-encode without chromakey.
VP9 alpha is most reliable in Chrome and Firefox. For Apple editors, download the ProRes MOV.