Images speak louder than words—but not to everyone. For visually impaired users and search engines, WCAG Image Alt Text serves as the voice of your visuals. Yet, even the most beautiful website can fall flat if its image descriptions are missing, inaccurate, or unoptimized.

That’s why performing an Alt Text Audit Checklist is not just a best practice—it’s essential for accessibility compliance, SEO performance, and following a proper WCAG Image Checklist.

In this blog, we’ll walk you through a step-by-step alt text audit checklist to ensure every image on your site is doing its job. Whether you’re an eCommerce store, content marketer, or web developer, this guide will help you fix the gaps and future-proof your content.

Before diving into the checklist, let’s understand why auditing your alt text is mission-critical:

• Accessibility: Ensure screen reader users can understand your images.
• SEO: Help Google index and rank your visuals.
• User Experience: Improve comprehension, engagement, and load fallback content.
• Compliance: Stay aligned with WCAG 2.1, ADA, or EN 301 549 standards.
  

A thorough audit reveals broken patterns, missing tags, keyword stuffing, and poor formatting—then helps you fix them.

Here’s a comprehensive alt text audit checklist you can use to optimize your website image by image.

1. Inventory All Images

Create a list of every image on your website. This includes:

• Product images
• Blog post visuals
• Header banners
• Icons or buttons (if functional)
• Decorative background elements
  

Tool Tip: Use AutoAlt.ai or a crawler like Screaming Frog to extract all image URLs and alt attributes.

2. Check for Missing Alt Text

Review which images have empty or missing alt attributes.

Must-have alt text:

• Informative images
• Functional icons
• Product or content visuals
  

No need for alt text:

• Purely decorative images (use alt=””)
  

3. Evaluate Alt Text Quality

For each image with alt text, ask:

• Does it describe the image clearly?
• Is it relevant to the page’s context?
• Does it sound natural for screen reader users?
  

Bad Alt Text: “image1”
Good Alt Text: “Woman wearing waterproof hiking jacket in the rain”

4. Incorporate Keywords Naturally

Evaluate if SEO keywords are included without stuffing. Your alt text audit checklist should flag:

• Keyword-stuffed alt text (bad)
• Missing keyword opportunities (fix)
• Unnatural phrasing just for SEO (revise)
  

Example:
“Organic cotton white t-shirt folded on a wooden table”
“buy organic cotton t-shirt best price eco shirt white shirt cotton”

5. Match Alt Text to Image Purpose

Alt text should vary based on why the image is used.

• Product image: Describe the product’s appearance
• Blog image: Reflect the article’s subject
• CTA button: Describe the action, not the icon
  

Tip: One image may need different alt text on different pages.

6. Check for Duplicated Alt Text

Many sites use the same generic alt text repeatedly.

Fix this by writing unique descriptions per image—even if they’re similar. This supports both SEO and screen readers.

7. Test with Screen Readers

Use tools like NVDA, VoiceOver, or JAWS to:

• Experience how screen readers interpret your content
• Identify alt text that feels awkward, unclear, or out of place
  

This human-centered test ensures accessibility in real-world use.

8. Fix Improperly Used Alt Tags

Watch for these red flags in your audit:

• Using alt on <div> or <span> tags (only valid for <img>)
• Missing alt=”” for decorative images
• Confusing alt with title tags (they serve different purposes)
  

9. Automate Future Compliance

To avoid manual rework in the future, install an AI-powered alt text generator like autoalt.ai. These tools use machine learning to:

• Analyze image content
• Understand surrounding context
• Generate descriptive, accessible, and SEO-friendly alt text at scale
  

Perfect for media-heavy websites, eCommerce platforms, and content libraries.

The Web Content Accessibility Guidelines (WCAG) set global standards to make websites accessible for everyone, including users who rely on screen readers. WCAG Image Alt Text is the short descriptive text added to an image that explains its meaning or purpose, allowing visually impaired users to understand the image content through assistive technology.

WCAG 2.1 SC 1.1.1 — Non-Text Content

According to WCAG 2.1 Success Criterion 1.1.1 (Non-Text Content), every meaningful visual element on a web page must include a text alternative that conveys the same information or function. In simple terms, this means:

• Informative images need descriptive alt text.
• Decorative visuals can have empty alt attributes (alt=””) to skip them for screen readers.
• Icons and functional images, such as buttons, must include alt text that describes their action (e.g., “Search,” “Play video,” or “Add to cart”).

WCAG Image Alt Text adds clear descriptions to photos, charts, and icons, improving accessibility and helping search engines understand images.

Why WCAG Image Alt Text Matters for SEO and Accessibility

Adding WCAG Image Alt Text improves accessibility and SEO by helping search engines understand images and ensuring visually impaired users can access content easily and meet WCAG compliance.

Examples of Good and Bad Alt Text

Here’s a simple comparison to understand what meets WCAG Image Alt Text standards:

Alt Text Presence

• Every informative image must include descriptive alt text.
• Use alt=”” only for decorative images.

Alt Text Accuracy

• Write alt text that explains the image’s purpose or meaning.
• Avoid vague labels like “image1” or “picture.”

Context Relevance

• Make sure the alt text fits the nearby content or link purpose.
• Example: For a “Buy Now” button image, alt text should say “Buy Now.”

Decorative Images

• Add alt=”” and role=”presentation” to purely decorative visuals.
• Keeps screen readers from reading unnecessary information.

Functional Images (Icons or Buttons)

• Describe the function, not the design.
• Example: “Search,” “Download PDF,” or “Submit Form.”

Complex Images (Charts or Infographics)

• Provide a brief summary or link to a full text description.
• Ensures all users get the same information.

Image File Names (Bonus Tip)

• Use descriptive names like wcag-image-checklist-chart.jpg.
• Helps SEO and supports WCAG compliance.

• AutoAlt.ai – AI-generated alt text and audit reports
• Screaming Frog SEO Spider – Find missing alt text and duplicate issues
• axe DevTools – Accessibility testing
• WAVE Web Accessibility Tool – Visual alt text review
• Google Lighthouse – Accessibility and performance reports

An alt text audit isn’t just for compliance—it’s a strategic move for growth. When done right, alt text, including WCAG image alt text, improves your search rankings, increases conversions, and makes your website accessible to everyone.

With this alt text audit checklist and WCAG image checklist, you have the roadmap to review, fix, and scale alt text across your site. Whether you’re doing it manually or using AI-powered tools like AutoAlt.ai, taking the time to optimize your image accessibility pays off—big time.