A Universal Specification for Website Technical Quality 🌐
Website Specification brings together requirements for semantics, SEO, accessibility, security, performance, i18n, and AI readiness.
Joost de Valk, the creator of Yoast SEO, has published the Website Specification initiative: an open checklist of technical capabilities and standards that any high-quality modern website should have.
Essentially, it’s an attempt to bring scattered best practices together into one clear manifesto.
The document is divided into key categories:
- Fundamentals and semantics: Valid HTML5, correct use of semantic tags, and proper character encoding.
- SEO and structured data: Schema.org markup, Open Graph, robots.txt, and XML sitemaps.
- Accessibility (a11y): Compliance with WCAG standards, mandatory alt attributes for images, and keyboard navigation support.
- Security: HTTPS, correct Content Security Policy (CSP) headers, and protection against clickjacking and XSS.
- Performance: Optimization for Core Web Vitals (LCP, INP, CLS), proper caching, and a modern compressed image format.
- Internationalization (i18n): Correct lang tags and hreflang attributes for multilingual websites.
- AI agent readiness (LLM-ready): Probably the trendiest item. The specification recommends serving clean content to AI bots and aggregators through Markdown endpoints, JSON-LD, and RSS instead of forcing them to parse a heavy JS mishmash.
The project is open, expanded by the community, and works perfectly as a ready-made technical brief for auditing any project.