A search crawler is functionally a blind user with a fast connection: it doesn't see your design, it parses your document structure. That's why almost everything accessibility demands — semantics, hierarchy, text alternatives, meaningful link names — is simultaneously an SEO input. And since June 2025 the European Accessibility Act (EAA) makes accessibility a legal requirement for most consumer-facing digital services in the EU: what used to be "nice to have" now carries fines.
The overlap: one fix, two beneficiaries
- Heading hierarchy (
h1→h2→h3, no skips, oneh1) is the document outline screen readers navigate by — and the structure crawlers and AI engines use to extract and quote sections. - Semantic landmarks (
<nav>,<main>,<article>,<footer>) tell assistive tech and parsers alike what each region is. A<div>soup ranks worse and fails audits. - Alt text serves screen readers and image search with the same string.
- Link names: "click here" fails WCAG (links must make sense out of context) and wastes anchor-text signal. One rewrite fixes both.
langattributes — on<html>and on inline foreign-language fragments — feed both screen-reader pronunciation and language detection for your hreflang setup.- CLS is an accessibility problem before it's a metric: layout jumps hit motor- and vision-impaired users hardest. Fixing Core Web Vitals is accessibility work.
Accessibility isn't a direct ranking factor, but its artifacts — parseable structure, lower bounce, wider usable audience — all are.
Next.js: enforce it in the pipeline
// .eslintrc — jsx-a11y catches missing alt, bad roles, unlabeled controls at PR time
{
"extends": ["next/core-web-vitals", "plugin:jsx-a11y/recommended"]
}
next/imagealready requiresalt— don't launder it withalt=""on meaningful images.- Set
<html lang={locale}>from your route param in the root layout. - Run Lighthouse accessibility alongside performance in CI — same tooling you already have for monitoring, one more score gate.
- Automated checks catch ~30–40% of WCAG issues; keyboard-only navigation of your top flows catches most of the rest. If you can't reach it with Tab, a crawler may not reach it with links either.
EAA: the deadline that ends the debate
Since June 28, 2025, the EAA applies to e-commerce, banking, transport, e-books and most consumer digital services sold in the EU (micro-enterprises under 10 staff and €2M are exempt). Enforcement is national and complaint-driven — an inaccessible checkout is now a legal exposure, not a backlog item. The practical bar is WCAG 2.1 AA (via EN 301 549), which is exactly the standard the fixes above target.
Checklist:
- One
h1per page; heading levels never skip; landmarks used semantically - Every meaningful image has real alt; every link makes sense out of context
-
langset from the locale on<html>and foreign-language fragments - jsx-a11y in ESLint + Lighthouse a11y gate in CI; top flows tested keyboard-only
- EAA applicability assessed; consumer flows meet WCAG 2.1 AA