🏠 New in Low Baseline Support: <link rel="preconnect">
January 15, 2020
The rel="preconnect" attribute for the <link> HTML element is a hint to the browser that the page or user is likely to request resources from another origin, so the browser should preemptively start a connection to the href value’s origin.
Source features
html.elements.link.rel.preconnect[mdn]