Hi Product Hunt, Joost here, founder of Yoast SEO. For years I've answered "what should my website actually do?" by pointing at six different sources: WHATWG, WCAG, IETF RFCs, schema.org, MDN, Google Search Central. None of them is a single, opinionated answer. So I built one. specification.website covers ten areas (foundations, SEO, accessibility, security, well-known URIs, agent readiness, performance, privacy, resilience, i18n). Every entry has a status — required, recommended, optional, or avoid — and 2–4 primary-source citations. No marketing fluff, no upsell, no login. What I think makes it different from existing "best practices" guides: - The bar for "required" is "the platform contract breaks without it" — not "we strongly recommend it" - It covers modern agent-readiness (llms.txt, MCP, Agent Skills, Web Bot Auth) alongside the classics - The site itself is the worked example — everything it recommends, it ships. MCP server, A2A endpoint, Markdown mirror via Accept content negotiation, strict CSP, the lot - All ten surfaces (HTML, /llms.txt, /llms-full.txt, RSS, sitemap, search index, MCP data) derive from one Markdown content collection It's free. MIT for code, CC BY 4.0 for content. Fork it, audit your site against it, send PRs when you disagree. Happy to answer anything about the technical choices or the editorial decisions about what's "required" vs "recommended".

The Website Specification

What a good website does, regardless of your stack

What a good website does, regardless of your stack