HTMLCat: A Sticky-Note Reference for Native HTML, CSS, and JS Tricks

HTMLCat is a browsable collection of “post-it” notes, each pairing a single native web-platform feature with a minimal example and the one caveat that actually matters in practice. The features span plain HTML, CSS, and JavaScript—plus the occasional shell snippet—and the emphasis is on using built-in browser capabilities rather than reaching for a framework or library. One highlighted example is detecting a device’s input capabilities directly from the platform.

The site is upfront about the risk that comes with living on the cutting edge: some notes cover features that are experimental or only partially supported. Its standing advice is to check each feature’s support label, always keep a fallback path, and test against real browsers and assistive technology rather than trusting a compatibility table alone—a nod to accessibility as a first-class concern.

(Note: the underlying tips did not come through in the fetched content—the page rendered only its section labels and framing text, with the individual post-its unpopulated—so this summary reflects the resource’s purpose and guidance rather than the specific techniques it catalogs.)