BrowserVersionOwn?TypeAs String
Chrome81.0.4044???
Chrome86.0.4240ownobject[object CustomElementRegistry]
Chrome88.0.4301???
Edge86.0.622ownobject[object CustomElementRegistry]
Edge87.0.651???
Edge87.0.658ownobject[object CustomElementRegistry]
Firefox68.0.0???
Firefox79.0.0ownobject[object CustomElementRegistry]
HeadlessChrome81.0.4044???
IE10.0.0???
Safari10.1.2ownobject[object CustomElementRegistry]

PropertiesChromeEdgeFirefoxHeadlessChromeIESafari
define 86.0.4240 86.0.622 79.0.0?? 10.0.0
get 86.0.4240 86.0.622 79.0.0?? 10.0.0
upgrade 86.0.4240 86.0.622 79.0.0?? 13.0.0
whenDefined 86.0.4240 86.0.622 79.0.0?? 10.0.0