Quick Tool for Checking Valid HTML Nesting
Alexander Vishnyakov has put together a handy single-page checker that answers a common front-end question: is it legal to nest one HTML element inside another? It’s a fast way to settle those "wait, can I do this?" moments.
Some cases are obvious — a <video> inside an <input> is a clear no. Others surprise even experienced devs. A <div> inside an <h1>? Invalid, and easy to trip over. Meanwhile, <div> breaks when placed in an <ol> but is perfectly fine inside a <dl> — the rules aren’t always intuitive.
