W3C

The World Wide Web Consortium (W3C) is the main international standards body for the World Wide Web, founded by Tim Berners-Lee in 1994. W3C develops web standards and guidelines to ensure the long-term growth of the Web, focusing on accessibility, internationalization, privacy, and security. W3C specifications include HTML, CSS, XML, SVG, WebAssembly, ARIA, WCAG, JSON-LD, Verifiable Credentials, and hundreds of other foundational web technologies. W3C operates through Working Groups, Interest Groups, and Community Groups that develop specifications through a consensus-based process, resulting in W3C Recommendations.

W3C publishes 5 APIs on the APIs.io network, including Affiliations API, Ecosystems API, Groups API, and 2 more. Tagged areas include Accessibility, Standards, Web, and Web Standards.

The W3C catalog on APIs.io includes 1 JSON-LD context and 2 Spectral governance rulesets.

W3C’s developer surface includes product news, engineering blog, YouTube channel, and 14 more developer resources.

🌐 Visit website 📡 Source on GitHub

41.8/100 thin ▬ flat Agent 22/100 agent aware Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1

AccessFreemium

15 APIs

AccessibilityStandardsWebWeb Standards

Kin Score

Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1

Composite quality — 41.8/100 · thin

Contract Quality 14.9 / 25

Developer Ergonomics 0.4 / 20

Commercial Clarity 7.9 / 20

Operational Transparency 4.8 / 13

Governance 8.3 / 12

Discoverability 5.6 / 10

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/w3c: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 15

Individual APIs this provider publishes, each with its own machine-readable definition.

Rate Limits 1

Documented rate limits and quota policies.

W3C Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

JSON Schema 1

Standalone JSON Schema definitions for this provider's data models.

AGENTIC

Resources

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Vocabulary

Vocabulary

JSONLDContext

JSONLDContext

SpectralRules

SpectralRules

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrg

GitHubOrg

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Learn 1

Tutorials, courses, talks, and written guidance

YouTube

YouTube

Company 5

The organization behind the API

Website

News

Blog

Mastodon

LinkedIn

Other 5

Properties that don't map to a standard resource type

TechnicalReports

API

Events

Donations

Sponsorship

Source (apis.yml)

aid: w3c
url: https://raw.githubusercontent.com/api-evangelist/w3c/refs/heads/main/apis.yml
name: W3C
description: The World Wide Web Consortium (W3C) is the main international standards body for the World Wide Web, founded
  by Tim Berners-Lee in 1994. W3C develops web standards and guidelines to ensure the long-term growth of the Web, focusing
  on accessibility, internationalization, privacy, and security. W3C specifications include HTML, CSS, XML, SVG, WebAssembly,
  ARIA, WCAG, JSON-LD, Verifiable Credentials, and hundreds of other foundational web technologies. W3C operates through Working
  Groups, Interest Groups, and Community Groups that develop specifications through a consensus-based process, resulting in
  W3C Recommendations.
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/w3c.png
tags:
- Accessibility
- Standards
- Web
- Web Standards
created: '2025-08-25'
modified: '2026-05-03'
specificationVersion: '0.19'
type: Index
access: 3rd-Party
position: Consumer
apis:
- aid: w3c:w3c-api
  name: W3C API
  description: The W3C API provides programmatic access to W3C data including specifications, working groups, editors, translations,
    and affiliations. It enables developers to query W3C's catalog of technical reports, discover active working groups, find
    specification editors and contributors, and access specification version history and status information.
  humanURL: https://api.w3.org/
  baseUrl: https://api.w3.org/
  tags:
  - API
  - Data
  - Specifications
  - Standards
  - W3C
  properties:
  - url: https://api.w3.org/doc
    type: Documentation
  - url: https://api.w3.org/
    type: BaseURL
  - url: https://github.com/w3c/w3c-api
    type: GitHub
- aid: w3c:wcag
  name: Web Content Accessibility Guidelines (WCAG)
  description: WCAG is the international standard for web accessibility, providing guidelines for making web content more
    accessible to people with disabilities. WCAG 2.2 is the current Recommendation, with WCAG 3.0 in development. Guidelines
    cover perceivability, operability, understandability, and robustness (POUR).
  humanURL: https://www.w3.org/TR/WCAG22/
  tags:
  - Accessibility
  - Guidelines
  - Standards
  - W3C
  properties:
  - url: https://www.w3.org/TR/WCAG22/
    type: Specification
  - url: https://www.w3.org/WAI/standards-guidelines/wcag/
    type: Documentation
  - url: https://github.com/w3c/wcag
    type: GitHub
- aid: w3c:html
  name: HTML Living Standard
  description: The HyperText Markup Language specification maintained by WHATWG as a living standard, published as a W3C Recommendation.
    HTML defines the semantic structure of web pages and forms the foundation of the web platform.
  humanURL: https://html.spec.whatwg.org/
  tags:
  - HTML
  - Standards
  - Web Platform
  properties:
  - url: https://html.spec.whatwg.org/
    type: Specification
  - url: https://www.w3.org/TR/html52/
    type: W3C Recommendation
  - url: https://github.com/whatwg/html
    type: GitHub
- aid: w3c:css
  name: CSS Specifications
  description: The Cascading Style Sheets (CSS) specification family maintained by the W3C CSS Working Group. CSS defines
    the presentation and styling of HTML documents. Key modules include CSS Grid Layout, Flexbox, Custom Properties, Animations,
    and CSS Functions and Mixins.
  humanURL: https://www.w3.org/Style/CSS/
  tags:
  - CSS
  - Standards
  - Styling
  - Web Platform
  properties:
  - url: https://www.w3.org/TR/CSS/
    type: Specification
  - url: https://www.w3.org/Style/CSS/Overview.en.html
    type: Documentation
  - url: https://github.com/w3c/csswg-drafts
    type: GitHub
- aid: w3c:json-ld
  name: JSON-LD
  description: JSON-LD (JSON for Linking Data) is a W3C Recommendation for encoding linked data using JSON. It provides a
    way to add semantic meaning to JSON documents through the use of @context, @id, and @type keywords, enabling interoperability
    through shared vocabularies like schema.org.
  humanURL: https://www.w3.org/TR/json-ld11/
  tags:
  - JSON
  - Linked Data
  - Semantic Web
  - Standards
  properties:
  - url: https://www.w3.org/TR/json-ld11/
    type: Specification
  - url: https://json-ld.org/
    type: Website
  - url: https://json-ld.org/playground/
    type: Playground
  - url: https://github.com/w3c/json-ld-syntax
    type: GitHub
- aid: w3c:verifiable-credentials
  name: Verifiable Credentials
  description: The Verifiable Credentials Data Model is a W3C Recommendation enabling cryptographically secure, privacy-respecting
    digital credentials. The VC family includes the data model, data integrity proof suites, and JSON Web Token/COSE encoding
    methods. VC 2.0 was published as a W3C Recommendation in 2025.
  humanURL: https://www.w3.org/TR/vc-data-model-2.0/
  tags:
  - Credentials
  - Identity
  - Privacy
  - Security
  - Standards
  properties:
  - url: https://www.w3.org/TR/vc-data-model-2.0/
    type: Specification
  - url: https://www.w3.org/groups/wg/vc/
    type: Working Group
  - url: https://github.com/w3c/vc-data-model
    type: GitHub
- aid: w3c:wasm
  name: WebAssembly
  description: WebAssembly (Wasm) is a W3C Recommendation defining a portable binary instruction format for a stack-based
    virtual machine. It enables near-native performance in web browsers for code compiled from languages like C, C++, and
    Rust, and is a core web platform technology.
  humanURL: https://www.w3.org/TR/wasm-core-2/
  tags:
  - Performance
  - Standards
  - WebAssembly
  - Web Platform
  properties:
  - url: https://www.w3.org/TR/wasm-core-2/
    type: Specification
  - url: https://webassembly.org/
    type: Website
  - url: https://github.com/WebAssembly/spec
    type: GitHub
- aid: w3c:aria
  name: WAI-ARIA
  description: Accessible Rich Internet Applications (WAI-ARIA) is a W3C Recommendation defining a set of HTML attributes
    that define ways to make web content and web applications more accessible to people with disabilities. ARIA roles, states,
    and properties supplement HTML semantics for dynamic content.
  humanURL: https://www.w3.org/TR/wai-aria-1.2/
  tags:
  - Accessibility
  - ARIA
  - Standards
  - W3C
  properties:
  - url: https://www.w3.org/TR/wai-aria-1.2/
    type: Specification
  - url: https://www.w3.org/WAI/ARIA/
    type: Documentation
  - url: https://github.com/w3c/aria
    type: GitHub
- aid: w3c:rdf
  name: RDF and SPARQL
  description: The Resource Description Framework (RDF) is a W3C standard for representing information in the web. RDF 1.2
    and SPARQL 1.2 are the latest versions, providing the foundation for the semantic web and linked data. RDF triples express
    knowledge as subject-predicate-object relationships.
  humanURL: https://www.w3.org/RDF/
  tags:
  - Linked Data
  - RDF
  - Semantic Web
  - SPARQL
  - Standards
  properties:
  - url: https://www.w3.org/TR/rdf12-primer/
    type: Specification
  - url: https://www.w3.org/TR/sparql12-overview/
    type: SPARQL Specification
  - url: https://github.com/w3c/rdf-star-wg
    type: GitHub
- aid: w3c:digital-credentials
  name: Digital Credentials API
  description: The W3C Digital Credentials API provides browser support for mediating presentation and issuance of digital
    credentials such as digital identity documents. It enables web applications to request and receive verifiable digital
    identity credentials from digital wallets in a privacy-preserving way.
  humanURL: https://www.w3.org/TR/digital-credentials/
  tags:
  - Credentials
  - Identity
  - Privacy
  - Security
  - Standards
  properties:
  - url: https://www.w3.org/TR/digital-credentials/
    type: Specification
  - url: https://github.com/w3c/digital-credentials
    type: GitHub
- aid: w3c:w3c-affiliations-api
  name: W3C Affiliations API
  description: The Affiliations API from W3C — 2 operation(s) for affiliations.
  humanURL: https://api.w3.org/
  tags:
  - Affiliations
  properties:
  - type: OpenAPI
    url: openapi/w3c-affiliations-api-openapi.yml
- aid: w3c:w3c-ecosystems-api
  name: W3C Ecosystems API
  description: The Ecosystems API from W3C — 1 operation(s) for ecosystems.
  humanURL: https://api.w3.org/
  tags:
  - Ecosystems
  properties:
  - type: OpenAPI
    url: openapi/w3c-ecosystems-api-openapi.yml
- aid: w3c:w3c-groups-api
  name: W3C Groups API
  description: The Groups API from W3C — 2 operation(s) for groups.
  humanURL: https://api.w3.org/
  tags:
  - Groups
  properties:
  - type: OpenAPI
    url: openapi/w3c-groups-api-openapi.yml
- aid: w3c:w3c-specifications-api
  name: W3C Specifications API
  description: The Specifications API from W3C — 3 operation(s) for specifications.
  humanURL: https://api.w3.org/
  tags:
  - Specifications
  properties:
  - type: OpenAPI
    url: openapi/w3c-specifications-api-openapi.yml
- aid: w3c:w3c-translations-api
  name: W3C Translations API
  description: The Translations API from W3C — 1 operation(s) for translations.
  humanURL: https://api.w3.org/
  tags:
  - Translations
  properties:
  - type: OpenAPI
    url: openapi/w3c-translations-api-openapi.yml
common:
- type: AgenticAccess
  url: agentic-access/w3c-agentic-access.yml
- type: DomainSecurity
  url: security/w3c-domain-security.yml
- url: https://www.w3.org/
  type: Website
- url: https://www.w3.org/TR/
  type: TechnicalReports
- url: https://api.w3.org/
  type: API
- url: https://github.com/w3c/
  type: GitHubOrg
- url: https://www.w3.org/news/
  type: News
- url: https://www.w3.org/blog/
  type: Blog
- url: https://www.w3.org/events/
  type: Events
- url: https://www.w3.org/donate/
  type: Donations
- url: https://w3c.social/@w3c
  type: Mastodon
- url: https://www.linkedin.com/company/w3c/
  type: LinkedIn
- url: https://www.youtube.com/@W3COfficial
  type: YouTube
- url: https://www.w3.org/sponsor/
  type: Sponsorship
- url: vocabulary/w3c-vocabulary.yml
  type: Vocabulary
- url: json-ld/w3c-context.jsonld
  type: JSONLDContext
- url: rules/w3c-rules.yml
  type: SpectralRules
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

W3C

APIs 15

Open Collections 1

Pricing Plans 1

Rate Limits 1

FinOps 1

Semantic Vocabularies 1

Spectral Rules 2