name	HTML
description	Avoid common HTML mistakes — accessibility gaps, form pitfalls, and SEO oversights.
metadata	{"clawdbot":{"emoji":"🌐","os":["linux","darwin","win32"]}}

width and height on <img> even with CSS sizing — browser reserves space before load
aspect-ratio in CSS as fallback — for responsive images without dimensions

autocomplete attribute is specific — autocomplete="email", autocomplete="new-password", not just on/off
<fieldset> + <legend> required for radio/checkbox groups — screen readers announce the group label
inputmode for virtual keyboard — inputmode="numeric" shows number pad without validation constraints
enterkeyhint changes mobile keyboard button — enterkeyhint="search", enterkeyhint="send"

Skip link must be first focusable — <a href="#main" class="skip">Skip to content</a> before nav
<th scope="col"> or scope="row" — without scope, screen readers can't associate headers
aria-hidden="true" hides from screen readers — use for decorative icons, not interactive elements
role="presentation" on layout tables — if you must use tables for layout (you shouldn't)

target="_blank" needs rel="noopener noreferrer" — noopener prevents window.opener access, noreferrer hides referrer
User-generated links need rel="nofollow ugc" — ugc tells search engines it's user content

<link rel="canonical"> prevents duplicate content — self-referencing canonical on every page
og:image needs absolute URL — relative paths fail on social platforms
twitter:card values: summary, summary_large_image, player — not arbitrary

<button type="button"> for non-submit — default is type="submit", triggers form submission
<dialog> element for modals — built-in focus trap and escape handling
<details> + <summary> for accordions — no JS needed, accessible by default
Void elements don't need closing slash — <img> not <img /> in HTML5, though both work

html

来源信息