WCAG 2.1 AA: A Plain-Language Guide for Business Owners

What WCAG Actually Is (and Why Courts Reference It)

WCAG stands for Web Content Accessibility Guidelines. It is a set of technical standards published by the World Wide Web Consortium (W3C) that define how websites should be built so people with disabilities can use them. Think of it as a rulebook for making your website work for everyone, including people who are blind, deaf, have limited mobility, or experience cognitive differences.

The standards themselves are not law. However, when someone files an ADA lawsuit claiming a website is inaccessible, courts consistently point to WCAG as the benchmark. Judges need a measurable standard to evaluate whether a site meets accessibility requirements, and WCAG is the closest thing to an agreed-upon yardstick. The Department of Justice has referenced WCAG 2.1 AA in guidance documents and settlement agreements, reinforcing its role as the de facto legal standard.

For Arizona business owners, this matters because ADA website lawsuits are not theoretical. They are actively filed in state and federal courts across the country, and Arizona businesses are not exempt. A plaintiff does not need to be your customer or even live in your state. If your website is publicly accessible and fails to meet basic accessibility criteria, you are exposed to legal risk.

The Four Principles in Plain English

WCAG organizes its guidelines around four core principles. Every requirement in the standard falls under one of these categories. Understanding them gives you a mental framework for evaluating your own site, even if you never read a single line of code.

Perceivable

Can everyone see and hear your content? This principle addresses whether the information on your site is presented in ways that all users can perceive, regardless of their sensory abilities. A person who is blind relies on screen reader software that reads text aloud. A person who is deaf needs captions to understand video content. If your site only communicates through visuals with no text alternatives, an entire segment of your audience is shut out.

Practical examples of perceivable requirements include:

Alt text for images - Every meaningful image needs a short text description so screen readers can convey what the image shows. A product photo without alt text is invisible to someone using assistive technology.
Captions for videos - Any video with spoken content needs synchronized captions. Auto-generated captions are a starting point, but they often contain errors that distort meaning.
Sufficient color contrast - Text must have a contrast ratio of at least 4.5:1 against its background. Light gray text on a white background might look elegant, but it fails this requirement and makes content difficult to read for people with low vision.

Operable

Can everyone use your menus and buttons? This principle focuses on navigation and interaction. Not every visitor uses a mouse. Some people navigate entirely with a keyboard. Others use voice commands or specialized input devices. If your site only works with a mouse, you are blocking access for people with motor impairments and many power users who prefer keyboard shortcuts.

Key operability requirements include:

Keyboard navigation works - Every interactive element on your site, including links, buttons, form fields, and dropdown menus, must be reachable and usable with the Tab, Enter, and arrow keys alone.
Skip links are present - A “skip to main content” link at the top of each page lets keyboard users jump past navigation menus. Without this, someone tabbing through your site has to pass through every menu item on every single page.
No time limits that lock users out - If your site has a session timeout or a timed form, users need a way to extend or disable the timer. People who rely on assistive technology often need more time to complete tasks.

Understandable

Is your content clear and predictable? Visitors should be able to read your text, understand your forms, and predict how your site behaves. This principle targets clarity, consistency, and helpful feedback. If your navigation changes layout between pages, or if a form silently fails without explaining what went wrong, you are creating unnecessary barriers.

Understandability requirements include:

Consistent navigation - Menus and navigation elements should appear in the same location and order across every page. Users build mental models of how your site works, and inconsistency breaks those models.
Clear form labels - Every input field needs a visible label that describes what information is expected. Placeholder text alone is not sufficient because it disappears once someone starts typing.
Helpful error messages - When a form submission fails, the error message should explain specifically what needs to be corrected. “Invalid input” is not helpful. “Please enter a valid email address” is.

Robust

Does your site work with assistive technology? This principle is about technical compatibility. Screen readers, magnification software, and alternative input devices all rely on your site’s underlying code to interpret content correctly. If the code is poorly structured, assistive technology cannot parse it reliably, and users experience broken layouts, missing information, or complete inability to navigate.

Robustness requirements include:

Semantic HTML - Using the correct HTML elements for their intended purpose. Headings should use heading tags, lists should use list tags, and buttons should be button elements. When a developer uses a generic tag styled to look like a button, screen readers cannot tell the user it is clickable.
Proper ARIA labels - ARIA (Accessible Rich Internet Applications) attributes provide extra information to assistive technology. For example, a search icon button needs an ARIA label like “Search” so screen readers announce its purpose rather than just saying “button.”
Valid code structure - Clean, well-formed HTML ensures that browsers and assistive technology interpret your content consistently. Broken markup can cause screen readers to skip sections or read content out of order.

The Most Common Failures

Certain accessibility problems appear over and over again across small business websites. Knowing the most frequent offenders helps you prioritize where to look first when evaluating your own site.

Missing alt text - This is the single most common accessibility failure on the web. Images without descriptive alt text are invisible to screen reader users. Every product photo, team headshot, and infographic on your site needs a text description.
Poor color contrast - Low-contrast text is difficult to read for people with low vision and uncomfortable for everyone else. Gray text on white backgrounds and white text on light-colored images are frequent culprits.
Non-keyboard accessible forms - Forms that require a mouse to complete, especially custom dropdowns and date pickers, exclude keyboard users entirely. Standard HTML form elements are keyboard accessible by default, but custom components often break this behavior.
Auto-playing media - Videos or audio that play automatically when a page loads create problems for screen reader users because the media audio competes with the screen reader’s voice output. If media must auto-play, it needs a visible and accessible pause button.
Missing language attribute - The HTML language attribute tells screen readers which language to use for pronunciation. Without it, a screen reader might try to read English text with French pronunciation rules, producing garbled output.

How to Audit Your Site Without Being Technical

You do not need to be a developer to check your website for basic accessibility problems. Several free tools and simple manual tests can reveal the most impactful issues in minutes.

Browser Extensions

Two free browser extensions can scan your site automatically and flag common problems:

WAVE (Web Accessibility Evaluation Tool) - Install this in Chrome or Firefox, visit any page on your site, and click the WAVE icon. It overlays your page with visual indicators showing errors, alerts, and structural elements. Red icons indicate failures that need immediate attention.
axe DevTools - Made by Deque Systems, this extension runs a thorough automated scan and organizes results by severity. It explains each issue in plain language and provides links to learn more about the specific WCAG criterion that was violated.

Built-In Contrast Checkers

Color contrast issues are among the easiest problems to detect. Free online tools like the WebAIM Contrast Checker let you enter your text color and background color to instantly see whether the combination meets the 4.5:1 ratio required by WCAG AA. If you are not sure what colors your site uses, your web developer or designer can provide the hex codes.

Keyboard-Only Testing

This is the simplest and most revealing manual test you can perform. Open your website in a browser, put your mouse aside, and try to use the entire site with only your keyboard. Press Tab to move between links and form fields. Press Enter to activate buttons. Use arrow keys for dropdown menus. Watch for the following issues:

Can you see where the keyboard focus is on every element? There should be a visible outline or highlight.
Can you reach every link, button, and form field using only the Tab key?
Can you open and close dropdown menus and modal dialogs with the keyboard?
Does focus ever get trapped in a section with no way to move forward or backward?

If you get stuck at any point or cannot tell where your keyboard focus is, those are real accessibility barriers that affect your users daily.

What “AA” Means vs “A” and “AAA”

WCAG defines three conformance levels, each building on the one before it. The level determines how strict the accessibility requirements are. Understanding these levels helps you know what courts expect and where your site should aim.

Level A - The Baseline

Level A covers the absolute minimum requirements. These are issues that, if left unaddressed, make your site completely unusable for some people. Examples include providing alt text for images, ensuring content is accessible without relying solely on color, and making sure all functionality is available through a keyboard. A site that fails Level A criteria has fundamental barriers that prevent access entirely.

Level AA - The Standard Courts Expect

Level AA includes everything in Level A plus additional requirements that address broader usability concerns. This is the level that the Department of Justice references in its guidance, and the level that courts most commonly require in settlement agreements and consent decrees. AA criteria include the 4.5:1 color contrast ratio, the ability to resize text up to 200% without losing content, and requirements for consistent navigation patterns. When someone says a website is “WCAG compliant,” they almost always mean AA.

Level AAA - The Highest Standard

Level AAA represents the most rigorous accessibility standard. It includes requirements like a 7:1 color contrast ratio, sign language interpretation for video content, and reading-level adjustments. Very few websites achieve full AAA conformance because some requirements are extremely difficult to meet for all types of content. The W3C itself acknowledges that AAA conformance across an entire site is not always possible. Most organizations target AA and implement specific AAA criteria where practical.

Compliance as a Competitive Advantage

Accessibility is often framed purely as a legal obligation. That framing misses the broader business value. A site built to WCAG AA standards is better for every visitor, not just those with disabilities.

Better experience for all users - The practices that make a site accessible also make it easier to use. Clear labels, logical navigation, readable text, and responsive layouts benefit every single person who visits your site. A parent browsing on their phone while holding a child benefits from the same large tap targets that help someone with limited motor control.
Improved SEO - Search engines and screen readers parse websites in similar ways. Alt text helps Google understand your images. Semantic HTML helps search crawlers identify your content structure. Proper heading hierarchy signals topic relevance. Sites that score well on accessibility audits tend to perform better in search results because they are fundamentally well-built.
Expanded market reach - According to the CDC, roughly 1 in 4 adults in the United States lives with a disability. In Arizona, that represents a substantial portion of your potential customer base. An inaccessible website effectively turns away customers who want to buy from you but physically cannot complete the transaction.
Stronger brand reputation - Businesses that prioritize accessibility signal that they care about all their customers. This builds trust and loyalty in ways that go beyond any single transaction. Conversely, a public ADA lawsuit creates negative press that is difficult to undo, even if you settle quickly.

The businesses that treat accessibility as a feature rather than a checkbox consistently outperform those that treat it as an afterthought. It is not about compliance for its own sake. It is about building a website that works for the widest possible audience and generates the most revenue.

Not sure if your website meets WCAG 2.1 AA standards? Schedule a free consultation to discuss an accessibility audit for your site.