fbpx Skip to main content
Digital AccessibilityWebsite Accessibility

WCAG 2.1 Explained: A Comprehensive Guide for Web Development Agencies

By June 24, 2024No Comments7 min read

For Digital Agencies creating accessible websites isn’t just a nice-to-have—it’s a necessity. As web development agencies, we have a responsibility to ensure that the sites we build are usable by everyone, regardless of their abilities or disabilities. This is where the Web Content Accessibility Guidelines (WCAG) 2.1 come into play. In this comprehensive guide, we’ll break down WCAG 2.1, explaining its importance, structure, and key principles to help your agency create more inclusive and accessible websites.

Understanding WCAG 2.1:

WCAG 2.1, published in June 2018, is an extension of WCAG 2.0. It provides additional success criteria to address mobile accessibility, people with low vision, and people with cognitive and learning disabilities. These guidelines are developed by the World Wide Web Consortium (W3C) and serve as the gold standard for web accessibility worldwide.

The Importance of WCAG 2.1 for Web Development Agencies:

  1. Legal Compliance: Many countries have laws requiring websites to be accessible, often referencing WCAG as the standard.
  2. Broader Audience Reach: Accessible websites can be used by a wider range of people, including those with disabilities.
  3. Improved User Experience: Many accessibility features benefit all users, not just those with disabilities.
  4. SEO Benefits: Many accessibility practices align with SEO best practices, potentially improving search rankings.
  5. Brand Reputation: Demonstrating a commitment to accessibility can enhance your agency’s reputation and attract socially conscious clients.

Structure of WCAG 2.1:

WCAG 2.1 is organized around four main principles, often referred to as POUR:

  1. Perceivable
  2. Operable
  3. Understandable
  4. Robust

Under each principle, there are guidelines and success criteria. Each success criterion is assigned one of three conformance levels: A (lowest), AA, or AAA (highest).

Let’s dive deeper into each principle:

1. Perceivable:

The Perceivable principle ensures that users can perceive the information being presented. It’s not just about seeing content; it’s about making sure content can be perceived in different ways.

Key Guidelines:

  • Provide text alternatives for non-text content
  • Provide captions and other alternatives for multimedia
  • Create content that can be presented in different ways without losing meaning
  • Make it easier for users to see and hear content

Example: Providing alt text for images allows screen reader users to understand the content of the image.


  1. Operable:

The Operable principle ensures that users can navigate and interact with all components of the interface.

Key Guidelines:

  • Make all functionality available from a keyboard
  • Give users enough time to read and use content
  • Do not use content that causes seizures or physical reactions
  • Help users navigate and find content
  • Make it easier to use inputs other than keyboard

Example: Ensuring that all interactive elements can be accessed and operated using only a keyboard benefits users who can’t use a mouse.


3. Understandable:

The Understandable principle ensures that users can comprehend the information as well as the operation of the user interface.

Key Guidelines:

  • Make text readable and understandable
  • Make content appear and operate in predictable ways
  • Help users avoid and correct mistakes

Example: Using clear and simple language, and providing definitions for any jargon or technical terms, helps users with cognitive disabilities and non-native speakers.

4. Robust:

The Robust principle ensures that content can be interpreted reliably by a wide variety of user agents, including assistive technologies.

Key Guidelines:

  • Maximize compatibility with current and future user tools

Example: Writing valid, semantic HTML ensures that content can be accurately interpreted by different browsers and assistive technologies.


Key Success Criteria in WCAG 2.1:

While all success criteria are important, here are some key additions in WCAG 2.1 that web development agencies should pay special attention to:

  1. 1.3.4 Orientation (AA): Content should not be restricted to a single display orientation, such as portrait or landscape, unless essential.
  2. 1.3.5 Identify Input Purpose (AA): The purpose of each input field collecting information about the user should be programmatically determinable.
  3. 1.4.10 Reflow (AA): Content should be presentable without loss of information or functionality, and without requiring scrolling in two dimensions for:
    •  Vertical scrolling content at a width equivalent to 320 CSS pixels
    • Horizontal scrolling content at a height equivalent to 256 CSS pixels
  4. 1.4.11 Non-Text Contrast (AA): Visual presentation of user interface components and graphical objects should have a contrast ratio of at least 3:1 against adjacent colors.
  5. 2.1.4 Character Key Shortcuts (A): If a keyboard shortcut uses printable character keys, the user should be able to turn it off, remap it, or have it active only on focus.
  6. 2.5.1 Pointer Gestures (A): All functionality that uses multipoint or path-based gestures for operation can be operated with a single pointer without a path-based gesture, unless essential.
  7. 2.5.2 Pointer Cancellation (A): For functionality that can be operated using a single pointer, at least one of the following is true:
    •   – No Down-Event
    •    – Abort or Undo
    •    – Up Reversal
    •    – Essential
  8. 4.1.3 Status Messages (AA): Status messages can be programmatically determined through role or properties such that they can be presented to the user by assistive technologies without receiving focus.

Implementing WCAG 2.1 in Your Web Development Process:

  1. Education: Ensure your team understands WCAG 2.1 principles and success criteria.
  2. Planning: Consider accessibility from the project’s inception, including it in project requirements and timelines.
  3. Design: Create designs with accessibility in mind, considering color contrast, font sizes, and layout.
  4. Development: Use semantic HTML, ARIA attributes when necessary, and ensure keyboard accessibility.
  5. Testing: Incorporate both automated and manual accessibility testing throughout the development process.
  6. Content: Train content creators on accessibility best practices, including writing alt text and using headings correctly.
  7. Ongoing Maintenance: Regularly audit and update sites to ensure continued compliance as content changes.

Tools for WCAG 2.1 Compliance:

Several tools can help your agency assess and maintain WCAG 2.1 compliance:

  1. AllAccessible: A suite of evaluation and remediation tools for web accessibility. AllAccessible helps identify and fix accessibility issues.
  2. Color Contrast Analyser: A tool for checking color contrasts against WCAG 2.1 standards.
  3. NVDA or VoiceOver: Screen readers for testing how your site performs with assistive technology.

WCAG 2.1 may seem daunting at first, but it’s an essential standard for creating truly inclusive websites. As web development agencies, we have the power—and the responsibility—to shape a more accessible web. By understanding and implementing WCAG 2.1, we not only comply with legal standards but also create better experiences for all users.

Remember, accessibility is not a checkbox to tick off but an ongoing process. It requires commitment, education, and regular testing. However, the benefits—including broader reach, improved user experience, and potential SEO advantages—make it a worthwhile investment.

By making WCAG 2.1 compliance a standard part of your web development process, your agency can position itself as a leader in creating inclusive digital experiences. In doing so, you’ll not only be doing the right thing but also adding significant value for your clients and their users.

Let’s work together to create a web that’s truly accessible to all. After all, as Tim Berners-Lee, the inventor of the World Wide Web, said: “The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect.”


Ready to Begin Your Website Accessibility Journey? Start Your Free Trial of AllAccessible Today!

Run a Free Accessibility Scan.

This field is for validation purposes and should be left unchanged.