The Popover API adds popover as an HTML attribute and popovertarget as a trigger. Click a button with popovertarget="menu" and the linked element becomes a popover.
It handles light-dismiss (clicks outside close it), top-layer rendering, and focus management. Pair it with the upcoming CSS Anchor Positioning API to attach popovers to triggers without JavaScript.
Browser support landed in Chrome 114 and Safari 17; Firefox is following in 2025. Treat it as a progressive enhancement and ship a click-based fallback for older browsers.