Using Gemini as Accessibility Checker

WCAG 2.1 Level AA

Using Gemini for Accessibility Checking

Unlike standard checkers that only scan code, Gemini’s multimodal nature — its ability to “see” images and “read” code simultaneously — makes it a powerful partner for accessibility. While it won’t guarantee WCAG 2.1 compliance, it can dramatically improve how you approach accessibility.

1. The Multimodal Advantage: “Seeing” Your UI

Traditional automated tools can tell you if an <img> tag is missing an alt attribute. Gemini goes further: it can look at a screenshot of your page and tell you if the alt text actually describes what is happening.

How to use it: Upload a screenshot of a complex component and try:

“Analyze this UI screenshot against WCAG 2.1 SC 1.1.1 (Non-text Content). Does the visual information provided here require specific alt text descriptions that aren’t obvious from the text alone?”

2. Analyzing Code for “Operable” Guidelines

WCAG 2.1 Level AA requires that all functionality be operable via a keyboard (Guideline 2.1). Gemini can perform static analysis on React, HTML, or Vue components to spot focus traps or missing ARIA labels.

How to use it:

“I am sharing a navigation component code snippet. Check it against WCAG 2.1 Level AA standards. Specifically, look for: correct use of ARIA roles, logical tab order, and visible focus indicators. Suggest fixes for any issues found.”

3. Simplifying “Understandable” Content

Guideline 3.1 of WCAG 2.1 focuses on making text readable and understandable. Gemini excels at plain language processing.

How to use it: Paste your website copy and ask:

“Rewrite this technical documentation to meet WCAG 2.1 Level AA ‘Understandable’ criteria. Aim for a lower secondary education reading level (SC 3.1.5) without losing the core meaning.”

4. Checking Color Contrast

Gemini can analyze a design mockup for contrast issues before anything is coded.

How to use it:

“Look at this mockup. Identify areas where text contrast might fail the 4.5:1 ratio for standard text (WCAG 1.4.3). Focus specifically on the ghost buttons and the footer text.”

5. Simulate User Perspectives

Accessibility is experiential, not just technical. Gemini can help simulate how different users might interact with your content — reflecting a broader shift from compliance to genuine usability.

How to use it:

“How might a screen reader user experience this page?”

“What cognitive accessibility issues might this interface create?”

6. Drafting Your Accessibility Statement

Once your checks are done, Gemini can help you communicate your commitment by drafting a Voluntary Product Accessibility Template (VPAT) or an Accessibility Statement based on your audit results.

Reminder: The “Human in the Loop” Rule

AI is a co-pilot, not the pilot.

  • Gemini can hallucinate: It may suggest an ARIA attribute that doesn’t exist or is deprecated.
  • Context matters: Gemini doesn’t know your specific user base’s needs as well as a human tester with a disability does.
  • Manual testing is non-negotiable: Always supplement Gemini’s checks with keyboard testing and screen reader (NVDA/VoiceOver) walkthroughs.

Quick Start: Gemini Accessibility Prompts

Goal Prompt Template
Alt Text Quality “Evaluate the descriptive quality of this image’s alt text: [Insert Text] based on this image: [Upload Image].”
Form Labels “Analyze this HTML form. Are the <label> tags correctly associated with inputs for screen readers?”
Error Handling “Review this error message logic. Does it meet WCAG 3.3.1 (Error Identification) by being specific and non-color reliant?”