WCAG 2.1 AA requirements
Web Content Accessibility Guidelines (WCAG) 2.1
Collection of tools and notes on Web accessibility
Introduction
Digital accessibility is about ensuring that websites, applications, and digital tools are usable by everyone, including people with disabilities.
Designing for accessibility is not just about compliance—it’s about creating inclusive experiences that improve usability for all users.
This article covers best practices for designing accessible user interfaces (UIs) and applications.
Understanding Accessibility and Disability Inclusion
Disability inclusion in digital products means considering the needs of users with various disabilities, including:
- Visual impairments (blindness, low vision, color blindness)
- Hearing impairments (deafness, hard of hearing)
- Motor disabilities (limited mobility, tremors, paralysis)
- Cognitive disabilities (dyslexia, ADHD, memory issues)
By designing with these users in mind, you create products that are more usable for everyone.
Principles of Accessible UI Design
1. Perceivable Content
- Use high contrast colors to enhance readability.
- Provide alternative text (
altattributes) for images. - Offer text transcripts and captions for audio and video content.
- Ensure that content is adaptable for assistive technologies like screen readers.
2. Operable Interfaces
- Ensure all interactive elements are keyboard accessible (e.g., buttons, links, forms).
- Avoid requiring precise mouse movements; provide large clickable areas.
- Support voice commands and alternative input methods.
- Allow users to pause, stop, or adjust animations that might trigger seizures or discomfort.
3. Understandable Information
- Use simple, clear language and avoid jargon.
- Provide descriptive headings and labels to aid navigation.
- Use consistent navigation and predictable UI patterns.
- Ensure form fields include helpful error messages and instructions.
4. Robust Technology
- Follow Web Content Accessibility Guidelines (WCAG).
- Use semantic HTML for proper screen reader interpretation.
- Ensure compatibility with assistive technologies like screen readers and braille displays.
- Test across different browsers and devices.
Best Practices for Accessible UI Design
Keyboard Navigation
Ensure all functionality is accessible via a keyboard (Tab, Enter, Arrow keys). Avoid relying on mouse-only interactions.
Responsive Design
Design for different screen sizes and orientations. Use relative units (em, rem, %) instead of fixed pixels for scalable text and elements.
Color and Contrast
- Use a contrast ratio of at least 4.5:1 for text.
- Avoid conveying information through color alone.
- Provide dark mode options for people with light sensitivity.
Forms and Inputs
- Label fields properly with
<label>elements. - Offer error messages that clearly describe issues.
- Support autofill and voice input for accessibility.
Multimedia Accessibility
- Provide captions for videos.
- Include descriptive transcripts for audio content.
- Ensure media players support keyboard controls.
Testing for Accessibility
Regularly test your UI with real users and assistive tools:
- Use screen readers like NVDA, JAWS, or VoiceOver.
- Run automated accessibility tests with Lighthouse, axe DevTools, or WAVE.
- Perform manual testing with keyboard-only navigation.
- Conduct usability studies with users who have disabilities.
Automated Accessibility Testing Tools
These tools scan your site and highlight WCAG compliance issues.
axe DevTools (by Deque)
- Browser extension (Chrome, Firefox, Edge)
- Detects WCAG 2.1 AA violations
- Free & paid versions
WAVE (by WebAIM)
- Online scanner & browser extension
- Highlights contrast, alt text, heading issues, etc.
- Free to use
Lighthouse (by Google)
- Built into Chrome DevTools
- Generates an accessibility audit report
- Free
- Open-source CLI tool for accessibility testing
- Can be automated for continuous testing
Siteimprove Accessibility Checker
- Browser extension
- Identifies WCAG issues in real time
- Paid advanced features
- API-based accessibility testing tool
- Good for developers integrating WCAG compliance checks
- AI-powered accessibility solution
- Helps automate compliance but can be controversial
Manual Testing & Simulators
Color Contrast Analyzer (by TPGi)
Helps check color contrast for WCAG compliance.NVDA (NonVisual Desktop Access)
Free screen reader to test usability for visually impaired users.JAWS
A paid screen reader that is commonly used by blind users.[VoiceOver (Mac/iOS) & TalkBack (Android)
Built-in screen readers to test mobile accessibility.
WCAG Conformance Logo
When you add a WCAG Conformance Logo to your website, you’re making a public statement about accessibility. But does your site truly meet those standards, or is it just a decorative sticker? Let’s explore why WCAG logos matter, how to use them properly, and what to avoid.
Why Display a WCAG Conformance Logo?
A WCAG Conformance Logo serves multiple purposes:
✅ Builds Trust – Users know your site follows accessibility best practices.
✅ Shows Commitment – Demonstrates that inclusivity is a core part of your design.
✅ Legal Protection – While not a guarantee, it shows an effort toward compliance.
✅ Encourages Accountability – Reminds developers to maintain accessibility over time.
However, slapping a WCAG badge on your site doesn’t automatically make it compliant.
Best Practices for Adding a WCAG Conformance Logo
1️⃣ Ensure Actual Compliance
Before adding a logo, test your site rigorously using:
- Automated Tools: axe DevTools, WAVE, Lighthouse
- Manual Testing: Screen readers, keyboard navigation
- Real User Feedback: Engage users with disabilities for testing
If your site doesn’t meet WCAG 2.1 AA or higher, don’t use the badge—fix accessibility issues first.
2️⃣ Choose the Right WCAG Level
WCAG has different levels of conformance:
| WCAG Level | Meaning |
|---|---|
| A | Basic accessibility fixes (minimum legal requirement) |
| AA | Industry standard (recommended for most sites) |
| AAA | The highest level (challenging for complex sites) |
⚠️ Be honest about your compliance level. Misleading claims can lead to legal trouble.
3️⃣ Link to an Accessibility Statement
Instead of just displaying a logo, provide a link to an accessibility statement.
This page should include:
- ✅ Your WCAG conformance level
- ✅ Testing methods used
- ✅ Areas that may not be fully compliant
- ✅ Contact details for accessibility feedback
Example:
| |