Understanding the Web Content Accessibility Guidelines (WCAG)

Accessing a website should be simple for everyone — yet many people with disabilities encounter digital obstacles that make everyday tasks frustrating, if not impossible. Web accessibility is all about removing those barriers.

Providing an accessible browsing experience isn’t just solving for an edge case, either. Globally, more than 1.3 billion people live with some type of disability that could prevent them from using your site — especially if it’s not built with accessibility in mind.

Fortunately, the Web Content Accessibility Guidelines (WCAG) can help you follow the best practices of accessible design — and eliminate accessibility barriers that could increase your business’s risk of legal action.

But who’s in charge of WCAG? And how do they decide which success criteria to include? What features do you need to follow to provide an accessible, compliant online experience? Below, we’ll answer those questions and provide an in-depth checklist to help you meet accessibility standards. 

Following the Web Content Accessibility Guidelines

The WCAG guidelines include specific requirements for making web content more accessible, but at their core, they’re based on four essential design principles that guide how a website should be built and designed.

Website Design and Principles of Digital Accessibility for WCAG Conformance

To achieve WCAG conformance, your website should meet the following four principles of accessible design — often referred to as the POUR principles:

• Perceivable: All information and user components must be presented in ways that users can perceive, whether through sight, sound, or touch. This could mean providing text alternatives (or alt text) for images, captions for videos, the ability to resize text, or ensuring sufficient color contrast for readability.

• Operable: Users must be able to navigate and interact with your digital content regardless of how they access it. This includes ensuring all functionality is available via a keyboard, giving users enough time to read content, and avoiding content that could trigger seizures.

• Understandable: Both the information and the user interface should be clear and easy to understand. This means writing in plain language, ensuring predictable navigation, and providing helpful instructions or error messages when users need guidance.

• Robust: Your website should work reliably across different technologies, including assistive technologies like screen readers or voice recognition software. Using clean, well-structured code ensures your website remains compatible as technology evolves.

These principles form the foundation for designing accessible digital experiences, and understanding them is the first step towards WCAG conformance.

WCAG Checklist for Digital Content

Along with the POUR principles, WCAG standards are divided into three conformance levels: Level A (basic), Level AA (mid-level), and AAA (highest). Most accessibility laws point to WCAG 2.1 Level AA as the standard for compliance. To help you meet those standards, here’s a breakdown of some of those criteria. 

Level A

• Provide text alternatives for non-text content, including alt text for images and images of text and captions for video or audio-only content.

• Ensure all web content is keyboard accessible (e.g., through keyboard commands and shortcuts) and avoids keyboard traps.

• Avoid content that flashes more than three times per second.

• Label form fields and controls clearly to help users understand the purpose of each field.

Level AA

• Ensure sufficient color contrast between text and background — WCAG recommends a minimum of 4.5:1 contrast ratio for normal text.

• Provide consistent navigation, including menus and headings, throughout your site.

• Make web pages appear and operate in predictable ways; more simply, avoid unexpected changes in your content.

• Provide users with enough time to interact with content, including the ability to extend or turn off time limits on time-based media.

• Ensure compatibility with assistive technologies by using semantic HTML and proper markup.

Level AAA

While Level AAA is not required for most legal compliance, the success criteria help enhance the user experience. If possible, try to incorporate a few of the level’s standards into your digital content, such as:

• Provide sign language interpretation for all pre-recorded audio content.

• Offer multiple ways to locate web pages, including site maps, search functionality, and navigation menus.

• Use simple language or provide supplemental content to accommodate lower-literacy users or non-native speakers.

• Provide context-sensitive help, such as explanations or guidance, near complex interactions or forms.

The checklist above isn’t exhaustive, but it does cover many of the most impactful areas for web accessibility across all three levels of conformance. For a more comprehensive list, check out our comprehensive WCAG checklist.

The card reads "WCAG: Web Content Accessibility Guidelines" with lines leading to three options. The first reads, "Level A, Minimum." The second reads, "Level AA, Recommended." And the third reads, "Level AAA, Highest."

Which Version of WCAG Should I Use to Test My Content?

WCAG gives businesses a clear, prescriptive way to test their web content for accessibility issues. To that end, however, each version of the guidelines is designed for backward compatibility: new versions of WCAG do not deprecate older versions. 

More simply, new versions of WCAG extend the requirements of older standards, meaning the old standards still apply to compliance requirements. 

A few other important things to know:

• Each level of WCAG includes all success criteria from the lower levels. In other words, Level AA includes all Level A success criteria, while Level AAA includes all Level A/AA success criteria.

• Generally, websites that meet Level AA requirements are considered reasonably accessible for most users with disabilities.

• As mentioned above, Level AAA is the strictest level, and some types of web content may be unable to meet the requirements.

So, which version of WCAG should you use for testing? For compliance with the Americans with Disabilities Act (ADA) and other accessibility laws, we recommend testing against WCAG 2.1 Level AA. 

Is WCAG a Legal Requirement?

Many international disability rights laws are based on WCAg. For example, the United States' Section 508 of the Rehabilitation Act requires state and local government websites to follow WCAG to maintain compliance. Additionally, the ADA, specifically Title III, requires private businesses to be accessible to individuals with disabilities in both physical and online spaces. While the Title does not explicitly mention WCAG or provide technical standards for online content, the Department of Justice has stated that WCAG will be used to measure compliance.

What Does the World Wide Web Consortium Do?

Founded in 1994, the World Wide Web Consortium (W3C) is the main international standards organization for the internet. That includes technical specifications for HTML, CSS, XML, and other technologies used to build websites.

In 1997, the W3C launched the Web Accessibility Initiative (WAI) to help people make their websites, mobile applications, online documents, and other digital content more accessible and usable to everyone. WAI develops technical reports about digital accessibility and recommends standards, namely, WCAG.

A Brief History of WCAG

Since its inception, WAI has updated WCAG several times to ensure the criteria still apply to new technologies.

Here’s an overview of the major milestones in WCAG’s development:

• May 5, 1999: The W3C publishes WCAG 1.0, which includes 14 guidelines with supporting checkpoints.

• December 11, 2008: WCAG 2.0 becomes an official recommendation. WCAG introduces the four principles of accessibility and 61 success criteria.

• June 5, 2018: WCAG 2.1 becomes an official recommendation. WCAG 2.1 introduces 17 new success criteria focused on mobile accessibility, cognitive accessibility, and low-vision accessibility.

• October 2023: WCAG 2.2 is released, adding nine new success criteria and deprecating one outdated criterion. You can read more about the new criteria in WCAG 2.2 here.

Eventually, WAI plans to introduce WCAG 3.0, a substantially different version of the guidelines that will be updated more frequently than WCAG 2.X.

A chart that breaks down the different WCAG milestones, from step 1 to step 6. In order, it reads: Editor's Draft, Working Draft, Wide Review Working Draft, Candidate Recommendation, Proposed Recommendation, and W3C Recommendation.

Understanding How WAI Maintains and Updates WCAG

New versions of WCAG must go through an extensive process before becoming an official recommendation. The WAI organizes this process through milestones. Here’s how it works:

1. New versions of WCAG begin as an Editor’s Draft, which may include the proposed success criteria from the WAI group, accessibility experts, and members of the disability community.

2. The WAI team publishes the document as a Working Draft and requests feedback from the wider accessibility community. Based on the feedback, the team updates the draft.

3. The draft becomes a Wide Review Working Draft and is published as a complete document. At this stage, members of the public are invited to leave comments.

4. After additional changes, the draft becomes a Candidate Recommendation. At this milestone, developers are encouraged to use the new version of WCAG to ensure that the standards can be implemented.

5. After additional comments are addressed, the Candidate Recommendation becomes a Proposed Recommendation. 

6. Members of the W3C can endorse a new version of WCAG. IF the new version receives “significant support” — including endorsement from the director of the W3C — it becomes an official W3C Recommendation. 

By design, reaching each milestone takes time. WCAG needs to apply to different types of digital content, and it needs to be reasonably future-proof — and if the W3C issued new versions of WCAG every year, organizations might have trouble keeping up with the changes.

Building a Strategy for WCAG Conformance and Digital Compliance

Making your digital content — whether it’s a web page, mobile app, online document, or online interface — accessible isn’t just a technical task. It’s a commitment to ensuring your site is accessible to all and compliant with the latest industry standards and requirements. 

The good news? WCAG offers a clear path forward. With a solid plan to test your content against WCAG 2.1 Level AA, you can detect and fix barriers that might keep users from accessing or using your site.

And with AudioEye, reaching WCAG conformance is even easier. With our three-pronged approach to accessibility, you can detect and fix accessibility issues and achieve industry-leading compliance with accessibility requirements. From our free Website Accessibility Checker that finds 32 WCAG violations (more than any other tool on the market) to our Expert Audits from accessibility experts and members of the disability community, AudioEye simplifies your path to accessibility.

Ready to see how accessible your existing content is? Get started with a free accessibility scan. 

Want to see how AudioEye provides up to 400% more protection than automation or consulting-only approaches? Schedule a demo.