HTML has been gobbling up swathes of what used to be JavaScript’s remit. This page lists a bunch of dynamic functionality that we can now achieve with just HTML. Update 2026-08-20 : I originally built this page in one hour during HTML Day 2026 to write and celebrate HTML, but I’ve since made some edits to better express and highlight where the browser implementation of some of this stuff is severely lacking and/or completely fails to meet accessibility needs. So, by all means, try it out, but make it as accessible as you can ! popover Browser Support: popover → Light dismiss, Esc to close, no managing z-index to wrangle it onto a top later. All managed with popover and popovertarget (and popovertargetaction ) attributes in HTML. ( MDN ) No JavaScript, just modern browser magic, thanks to the wonderful folks speccing for the web and building our browsers!…