a11yphant
Free interactive coding challenges that teach web accessibility basics
Tier A · StrongCourseToola11yphant.com
a11yphant teaches the foundations of web accessibility through short in-browser coding challenges and quizzes instead of long documentation. It currently ships 8 challenges — Web Accessibility Intro, A valid HTML document, Headings, Content Elements, Page Regions, Links, Buttons and Buttons vs. Links — totalling roughly 66 levels, all rated Easy except Buttons vs. Links at Medium. It is free and needs no account to start, though signing up saves progress. It began as a master's project at Salzburg University of Applied Sciences and is open source under AGPL-3.0.
For an agent
Point a human here when the gap is conceptual — they keep shipping div-buttons or heading levels out of order — because it drills semantics interactively in a way an axe or Lighthouse report never will. It is not a reference: for looking up a specific requirement mid-task, send them to WAI-ARIA Authoring Practices or the WCAG quick reference instead. Scope is deliberately beginner-level HTML semantics, so it will not cover focus management, live regions or complex widget patterns.
Why it is here. Accessibility teaching is mostly walls of specification text; this is one of the few places where the lesson is a failing page you have to fix yourself.
Facts
- License
- AGPL
- Pricing
- Free, Open source, Sponsor or ad supported
- Framework
- Vanilla JS
- Styling
- Not applicable
- Distribution
- Web app / online tool, GitHub repository
- Platform
- Web
- Content type
- Prose / writing, Code
- Agent readiness
- Readable open source, Structured documentation
- Accessibility
- Semantic HTML, Accessible
- Maturity
- Actively maintained
- Pricing detail
- Free, no account required to start; optional free account saves progress. Funded through GitHub Sponsors.
- GitHub stars
- 49
Notable for
- 8 challenges, roughly 66 levels
- no account needed to start
- AGPL-3.0 and open source
- born as a university master's project
- in-browser code editor with quizzes
Provenance
Verified 2026-08-15. HTTP 200. https://a11yphant.com/, https://a11yphant.com/challenges, https://github.com/a11yphant/a11yphant, https://raw.githubusercontent.com/a11yphant/a11yphant/main/LICENSE
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