wcag-power-platform

WCAG 2.1 for Web Apps & Power Platform

This skill makes anything you build or review conform to WCAG 2.1 Level AA (the legal default for most public-sector and EU/UK accessibility law), while flagging the AAA criteria worth reaching for. It covers generic web content, full HTML pages/sites and SPAs, and modern theming (dark mode, high contrast, design tokens), and the four Power Platform component types: PCF controls, model-driven apps/forms, canvas apps, and Power Pages.

Default target

Unless the user states otherwise, conform to Level AA. Level A is the floor and AA is what regulations (ADA, Section 508, EN 301 549 / UK Public Sector Bodies Accessibility Regulations) actually require. Mention AAA only as an optional enhancement.

How to use this skill

1. Identify the component type (web/PCF/model-driven/canvas/Power Pages). The platform changes how you satisfy a criterion — see the routing table below and read the matching reference file.
2. Author or review against the four principles. Read references/wcag-checklist.md — it lists every WCAG 2.1 success criterion grouped under Perceivable, Operable, Understandable, Robust, with the concrete, testable thing to check for each. This is the heart of the skill.
3. Apply the platform-specific guidance from the relevant reference file.
4. Self-verify using the verification section below before declaring done.

When building something new, bake the checks in as you write — don't bolt them on afterwards. When auditing, report findings as a table: criterion, level (A/AA/AAA), pass/fail, location, and the fix.

Component routing

Always read references/wcag-checklist.md — every other file assumes it and only adds deltas. Read references/html-pages.md for any standalone page/site/SPA, and references/theming.md whenever colour schemes, dark mode, high-contrast, or a design-token/theme system is in play (these stack with the platform files — e.g. a themed Power Pages site reads the checklist + power-pages + theming).

The four principles (POUR) — quick orientation

• Perceivable — users can perceive the information: text alternatives, captions, colour not used alone, 4.5:1 text contrast / 3:1 large text & UI, reflow to 320px, resizable text, programmatic structure.
• Operable — users can operate it: full keyboard access, no keyboard traps, visible focus, logical focus order, enough time, no seizure-inducing flashing, target size, skip links, descriptive link text.
• Understandable — readable and predictable: page language set, labels and instructions on inputs, clear error identification + suggestions, consistent navigation, no surprise context changes on focus/input.
• Robust — works with assistive tech: valid markup, correct name/role/value for every control, status messages announced via live regions.

The highest-leverage AA checks (apply to everything)

These catch the majority of real failures. Verify every one before finishing:

1. Every interactive element is keyboard reachable and operable (Tab/Shift+Tab, Enter/Space), with a visible focus indicator (2.4.7) and no keyboard trap (2.1.2).
2. Every form control has a programmatic label (<label for>, aria-label, or aria-labelledby) — not just a visual placeholder (1.3.1, 3.3.2, 4.1.2).
3. Every meaningful image has alt text; decorative images have empty alt (alt="") or are hidden from AT (1.1.1).
4. Text contrast ≥ 4.5:1 (≥ 3:1 for large text ≥ 18.66px bold / 24px), and UI components & graphical objects ≥ 3:1 (1.4.3, 1.4.11).
5. Colour is never the only way information is conveyed (1.4.1) — pair it with text, icon, or pattern.
6. Semantic structure: real headings in order (h1→h2→h3, no skips), lists as lists, one <main>, landmark regions, tables with <th scope> (1.3.1).
7. Page/screen has a descriptive title and lang is set (2.4.2, 3.1.1).
8. Dynamic updates are announced to screen readers via aria-live / status roles (4.1.3).
9. Content reflows with no horizontal scroll at 320 CSS px / 400% zoom and text resizes to 200% without loss (1.4.10, 1.4.4).
10. Errors are identified in text, near the field, with a suggested fix, and the field is linked via aria-describedby (3.3.1, 3.3.3).

Verification before "done"

Run through these — automated tools catch ~30–40%, the rest needs the manual checks:

• Automated: axe-core / Accessibility Insights / Lighthouse / WAVE. For Power Platform, also the built-in App Checker (model-driven & canvas) and the Accessibility checker in the canvas studio. Treat these as a first pass, not proof of conformance.
• Keyboard-only pass: unplug the mouse. Tab through the whole UI. Can you reach and operate everything? Is focus always visible? Does order make sense? Can you always Tab back out (no trap)?
• Screen reader spot-check: NVDA or JAWS (Windows) / VoiceOver (Mac). Is every control announced with a sensible name, role, and state? Are errors and dynamic changes announced?
• Zoom/reflow: 400% browser zoom (≈320px). No two-dimensional scrolling for non-data content; nothing clipped or overlapping.
• Contrast: spot-check text and UI against the 4.5:1 / 3:1 thresholds with a contrast checker; verify in any dark/high-contrast theme too.
• Themes: re-run the contrast, focus-visibility, and colour-only checks in every theme variant you ship — light, dark, and OS high-contrast / forced-colors (see references/theming.md). Conformance is not inherited from the default theme.
• Colour-only: would the meaning survive in greyscale?

If a criterion genuinely can't be met (e.g. essential complex data viz), say so explicitly and propose the closest accessible alternative rather than silently skipping it.

Note on standards version

This skill targets WCAG 2.1. WCAG 2.2 (a superset) adds nine more criteria — notably Focus Not Obscured (2.4.11/2.4.12), Dragging Movements (2.5.7), Target Size Minimum 24×24px at AA (2.5.8), Consistent Help (3.2.6), Redundant Entry (3.3.7), and Accessible Authentication (3.3.8). If the user asks for 2.2 or you're targeting current best practice, also apply those; the checklist notes where they extend 2.1.