# The Website Specification

> Source: <https://specification.website/>
> Published: 2026-05-31 07:09:50+00:00

# What a good website does.

A platform-agnostic specification of the technical features every
decent website should have — from `<title>`

to `/.well-known/security.txt`

,
from WCAG contrast to `llms.txt`

.
Written for humans and agents.

## Categories

Ten areas, mapped to widely-accepted standards.

[All topics →](/spec/)

-
### Foundations

14The HTML, head, and document basics every page needs.

-
### SEO

13Search visibility — robots.txt, sitemaps, canonicals, structured data.

-
### Accessibility

20WCAG-aligned rules so people of all abilities can use the site.

-
### Security

12Headers, transport, and policies that keep visitors safe.

-
### Well-Known URIs

9Standard, agreed-upon paths under /.well-known/.

-
### Agent Readiness

18Things that make a site legible to AI agents and crawlers.

-
### Performance

19Core Web Vitals, caching, images, fonts, network behaviour.

-
### Privacy

6Consent, signals, and respecting visitor choice.

-
### Resilience

5Graceful failure — error pages, offline, redirects.

-
### Internationalisation

12Language, locale, direction, and translated content.

### Standards, not opinions

Each topic links back to the source standard — WHATWG, W3C, IETF RFCs, WCAG, MDN, and the organisations defining the modern web.

### Platform agnostic

Whether you ship WordPress, Drupal, TYPO3, Next.js, Astro, Hugo, a Django app, or plain HTML, the spec is the spec. Implementation hints follow it, not the other way round.

### Built in the open

Every page has an [Edit on GitHub](https://github.com/jdevalk/specification.website) link. PRs welcome. Sources credited on every page.

## Let your agent query the spec.

The whole spec is available as an open [MCP](https://modelcontextprotocol.io/) server — read-only, no auth — plus a published [Agent Skill](/.well-known/agent-skills/specification-website/SKILL.md) that teaches any compatible agent when and how to use it. Per-page Markdown is available via `/llms.txt`

and `Accept: text/markdown`

on any spec URL.

```
{
  "mcpServers": {
    "specification-website": {
      "transport": "http",
      "url": "https://mcp.specification.website/mcp"
    }
  }
}
```

## How to use this site

- 01
### Audit

Run through the

[checklist](/checklist/). Each item is a “does the site do this — yes or no.” - 02
### Learn

Click into any item for what it is, why it matters, and how to implement it.

- 03
### Improve

Found a gap, a stale fact, or a missing topic? Open a PR. Sources required.