Accessibility June 25, 2025

WCAG 2.1 Compliance Made Simple

Learn how to make your website accessible to everyone with proper alt text that meets WCAG 2.1 AA standards and works with screen readers.

Web accessibility isn't just a legal requirement—it's a moral imperative and a business opportunity. With over 1 billion people worldwide living with disabilities, making your website accessible opens your content to a massive audience while avoiding potential lawsuits.

The Web Content Accessibility Guidelines (WCAG) 2.1 provide the gold standard for web accessibility. While the guidelines can seem overwhelming, understanding how to properly implement alt text is one of the most impactful steps you can take.

Understanding WCAG 2.1 Image Requirements

WCAG 2.1 Level AA compliance requires that all non-text content has a text alternative that serves the equivalent purpose. For images, this primarily means providing appropriate alt text that conveys the same information as the image.

Key WCAG 2.1 Success Criteria for Images:

  • 1.1.1 Non-text Content (Level A): All images must have text alternatives
  • 1.4.5 Images of Text (Level AA): Use actual text rather than images of text
  • 2.5.3 Label in Name (Level A): Accessible names must contain visible label text

Types of Images and Their Alt Text Requirements

1. Informative Images

These images convey important information that isn't available in the surrounding text. They require descriptive alt text that communicates the same information.

Example: A graph showing quarterly sales

Alt text: "Bar graph showing Q1 sales at $2.1M, Q2 at $2.8M, Q3 at $3.2M, and Q4 at $3.9M"

2. Decorative Images

Images that are purely decorative and don't add information should have empty alt text (alt="") so screen readers skip them entirely.

Example: Background patterns or divider lines

Alt text: alt="" (empty but present)

3. Functional Images

Images used as links or buttons need alt text that describes the function, not the appearance.

Example: Printer icon that prints the page

Alt text: "Print this page" (not "Printer icon")

4. Complex Images

Charts, diagrams, and infographics need both concise alt text and a longer description available nearby.

Example: Detailed flowchart

Alt text: "Flowchart of user onboarding process"

Long description: Full text description in surrounding content or linked page

Common WCAG Alt Text Mistakes

Avoid These Common Errors:

  1. Missing alt attributes: Every img tag must have an alt attribute, even if empty
  2. Redundant phrases: Don't use "image of" or "picture of"
  3. File names as alt text: "IMG_1234.jpg" provides no useful information
  4. Keyword stuffing: Alt text should describe, not optimize for SEO
  5. Overly long descriptions: Keep alt text concise (typically under 125 characters)
  6. Repeating captions: If a caption fully describes the image, use empty alt text

Screen Reader Compatibility

Understanding how screen readers interpret alt text helps you write better descriptions. Popular screen readers include JAWS, NVDA, VoiceOver, and TalkBack.

Screen Reader Best Practices:

  • Keep alt text concise—screen readers announce "graphic" before reading alt text
  • Use proper punctuation for natural pauses
  • Avoid ASCII art or emoticons that sound confusing when read aloud
  • Test with actual screen readers when possible
  • Consider the reading order and context

Testing for WCAG Compliance

Regular testing ensures your alt text meets WCAG standards. Here are essential testing methods:

Automated Testing Tools

  • WAVE (WebAIM's Web Accessibility Evaluation Tool)
  • axe DevTools browser extension
  • Lighthouse (built into Chrome DevTools)
  • Pa11y command line tool

Manual Testing

  • Disable images and read only the alt text
  • Use a screen reader to navigate your site
  • Check for context and clarity
  • Verify functional images work correctly

Legal Implications

Web accessibility lawsuits have increased dramatically, with over 4,000 filed in 2022 alone. Courts consistently rule that websites are places of public accommodation under the ADA.

Legal Requirements by Region:

  • United States: ADA Title III requires accessible websites
  • European Union: EN 301 549 standard based on WCAG 2.1
  • Canada: AODA requires WCAG 2.0 Level AA
  • Australia: DDA covers digital accessibility

Writing Effective Alt Text: A Step-by-Step Guide

  1. Identify the image type: Is it informative, decorative, functional, or complex?
  2. Consider the context: What information does the surrounding content already provide?
  3. Write a first draft: Describe what you see objectively
  4. Refine for clarity: Remove redundancy and improve flow
  5. Check the length: Aim for under 125 characters when possible
  6. Test with tools: Use accessibility checkers to verify

Real-World Examples

E-commerce Product Image

Poor: "shoe.jpg"

Better: "Red running shoe"

Best: "Nike Air Max red running shoe with white sole, side view"

News Article Photo

Poor: "Image"

Better: "CEO speaking at conference"

Best: "CEO Jane Smith presenting quarterly results at investor conference"

Scaling Accessibility with AI

While manual alt text creation ensures the highest quality, it's not always practical for websites with thousands of images. AI-powered tools can help scale accessibility efforts while maintaining WCAG compliance.

Modern AI can analyze images and generate contextually appropriate alt text that meets accessibility standards. The best tools understand the difference between decorative and informative images, avoiding unnecessary descriptions while ensuring all important content is accessible.

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Conclusion

WCAG 2.1 compliance doesn't have to be complicated. By focusing on proper alt text implementation, you can make your website accessible to millions of users with disabilities while improving SEO and avoiding legal issues.

Remember, accessibility is an ongoing process, not a one-time fix. Regular testing, user feedback, and staying updated with guidelines ensures your website remains accessible to all users, regardless of their abilities.

Start with alt text—it's one of the simplest yet most impactful accessibility improvements you can make. Your users (and your legal team) will thank you.