Web standards

Web Hypertext Application Technology Working Group

WHATWG maintains the living standards for HTML, DOM, Fetch, and URL — the everyday browser primitives. Run by Apple, Google, Microsoft, and Mozilla via a Living Standard process.

Short name: WHATWG
Scope: Web standards
Homepage: whatwg.org
Standards governed: 3

Standards governed by WHATWG

Heading hierarchy HTML Living Standard global SEO Exactly one H1 per page, descending hierarchy, no skipping levels. The cheapest SEO and accessibility check that exists.
Resource hints (preconnect / preload / prefetch / dns-prefetch) WHATWG HTML Living Standard global Performance Tell the browser which connections, fonts, scripts, and next-pages it should warm up before they're strictly needed. Single-digit-percent LCP improvements per hint, multiplied across a page.
X-Content-Type-Options: nosniff Fetch Standard global Security Tells the browser to trust your declared Content-Type instead of guessing. Stops 'I uploaded a JPG that was actually JavaScript' attacks dead.