jdevalk

jdevalk / specification.website

Public

Website specification — HTML, accessibility, security, SEO, agent-readiness. Platform-agnostic, sourced, MIT.

specification.website accessibility agent-readiness astro cloudflare-pages llms-txt
28
3
100% credibility
Found May 29, 2026 at 53 stars -- GitGems finds repos before they trend. Get early access to the next one.
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AI Analysis
TypeScript
AI Summary

The Website Specification is a free, open-source reference guide that defines exactly what a good website should do. It covers ten areas: basic HTML structure, search engine optimization, accessibility for all users, security headers, standard web paths, compatibility with AI assistants, page speed, privacy practices, error handling, and internationalization. The project includes a searchable website where you can browse topics, a checklist to audit your own site, and a special interface that AI assistants can use to look up guidance while helping you build. Every page cites official sources like WHATWG, W3C, and IETF standards. The content is freely available under Creative Commons license, and anyone can contribute improvements through the project's GitHub repository.

How It Works

1
🔍 You discover the specification

You hear about a comprehensive guide that tells you exactly what a good website needs — from SEO to security to accessibility.

2
🌐 You visit the website

You browse through ten clear categories covering everything a modern website should do, with each topic explained in plain language.

3
✨ You search for what you need

You type a question like 'content security policy' or 'image alt text' and instantly find the relevant guidance with step-by-step instructions.

4
You connect an AI assistant
🔌
Connect via MCP

Your AI assistant can query the specification directly, search topics, and get full guidance pages.

📄
Read the plain text version

AI crawlers automatically get a clean text version of the entire specification to read.

5
✅ You check your own website

You use the checklist to audit your site against the specification and see exactly what you're doing right and what needs fixing.

🎉 Your website is spec-compliant

You have a clear roadmap for building a website that follows web standards, ranks well in search, works for everyone, and stays secure.

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Star Growth

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AI-Generated Review

What is specification.website?

It's a comprehensive, platform-agnostic specification of what makes a good website. Built with TypeScript and Astro, it documents everything from HTML basics and SEO requirements to security headers, WCAG accessibility rules, and how to make a site legible to AI agents. Every claim cites official sources like the WHATWG HTML Living Standard, W3C WCAG 2.2, and IETF RFCs. The project includes a built-in MCP server so AI agents can query the spec directly, plus generates llms.txt, RSS feeds, and sitemap XML automatically.

Why is it gaining traction?

The project fills a gap: most web standards documentation is fragmented across W3C, IETF, browser docs, and search engine guidelines. This consolidates everything into one readable spec with clear status levels (Required, Recommended, Optional, Avoid). As AI agents become more prevalent, the MCP endpoint and llms.txt generation make it uniquely useful for sites that want to be discovered and interpreted by machine clients. It explicitly refuses to recommend specific frameworks or stacks, which earns trust from developers tired of marketing-heavy documentation.

Who should use this?

Frontend developers building production websites who want a checklist of what to get right. SEO engineers verifying their implementations against spec requirements. Accessibility teams auditing against WCAG guidance. AI engineers building crawlers or agentic tools that need a machine-readable web standards reference. The MCP tools are particularly useful if you're building agents that need to audit sites against web standards.

Verdict

This is a credible reference tool with a narrow scope executed well. The 28 stars and 1.0% credibility score reflect early-stage maturity rather than a quality problem—the spec content itself is well-sourced and practical. If you need a web standards reference you can trust or an MCP endpoint your agents can query, it is worth bookmarking. Do not confuse low GitHub popularity with low technical value; the author (Joost de Valk) has deep domain credibility in SEO and web performance. Use it as a reference, not as a framework you build around.

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