Web Accessibility Alt Text AI Prompts for Content Editors

Alt text is one of the most important accessibility features on the web, yet it is also one of the most frequently neglected or poorly implemented. Alt text provides a text alternative for images, enabling users who cannot see images to understand what they convey. This includes users with visual impairments who use screen readers, users who have images disabled due to slow connections, and search engines that cannot see images directly. When alt text is missing, vague, or unhelpful, the experience for these users degrades significantly. Creating effective alt text requires understanding what information images convey and translating that into words. AI tools help content editors generate alt text that is specific, descriptive, and genuinely useful.

TL;DR

• Alt text is essential for web accessibility: It is the bridge between visual content and non-visual access
• AI helps generate alt text at scale: Content editors can produce better alt text more efficiently with AI assistance
• Effective alt text is specific and descriptive: Generic descriptions like “image” or “graphic” provide no value
• Context determines what alt text should say: The same image might need different alt text depending on how it is used
• SEO benefits from proper alt text: Alt text that describes images also helps search engines understand your content
• Review is still necessary: AI-generated alt text should be reviewed for accuracy and appropriateness

Introduction

Alt text serves multiple constituencies simultaneously. For users with visual impairments who rely on screen readers, alt text is the only way to access the information conveyed by images. For users in bandwidth-constrained environments who disable images, alt text appears in place of images. For search engines, alt text provides signals about image content that inform ranking. For all these users, alt text that is missing, generic, or inaccurate creates a degraded experience.

The challenge of writing good alt text is that it requires understanding what information an image conveys and translating that into words. This sounds simple but is surprisingly complex in practice. Informative images need alt text that describes the information the image conveys. Decorative images need alt text that is intentionally empty so screen readers skip them. Complex images like charts need longer descriptions that convey the full data. Getting this wrong in either direction creates problems.

AI tools help content editors generate appropriate alt text by analyzing images and suggesting descriptions. The key is knowing how to prompt AI to produce alt text that meets accessibility standards rather than generic descriptions that technically satisfy accessibility checkboxes without actually helping users.

Table of Contents

1. Understanding Alt Text Fundamentals
2. Different Image Types and Their Alt Text Needs
3. Writing Alt Text for Informative Images
4. Handling Decorative Images Correctly
5. Describing Complex Images Like Charts and Graphs
6. Generating Alt Text with AI Prompts
7. Reviewing and Refining AI-Generated Alt Text
8. Applying Alt Text Best Practices Across Content
9. Measuring Alt Text Quality
10. Frequently Asked Questions

Understanding Alt Text Fundamentals

Alt text is governed by WCAG (Web Content Accessibility Guidelines) principles that define what makes alt text effective. Understanding these principles provides the foundation for creating accessible content.

The four alt text principles are that every meaningful image should have alt text, decorative images should have empty alt text, alt text should convey the information or function of the image, and alt text should be concise while being complete. Violations of these principles are the most common accessibility failures.

Fundamentals prompts should request explanation of WCAG alt text requirements, identification of common alt text mistakes and how to avoid them, guidance on when alt text is required versus when it can be omitted, and assessment criteria for evaluating alt text quality.

Different Image Types and Their Alt Text Needs

Different images serve different purposes and require different alt text treatments. Understanding image types helps determine the right approach.

Image types include informative images that convey information users need to understand content, decorative images that add visual interest but convey no information, functional images that initiate actions like submit buttons, text images that contain text that appears in the image, and complex images like charts and diagrams that convey detailed information.

Type-specific prompts should request identification of the image type based on its context, guidance on the correct alt text treatment for each type, examples of correct and incorrect alt text for each type, and processes for determining image type when context is unclear.

Writing Alt Text for Informative Images

Informative images convey information that alt text should communicate. The goal is to describe what the image shows and why it matters in context.

Effective alt text for informative images is specific rather than generic, captures the relevant information the image conveys, and is concise while being complete. It describes the content and context, not just the visual elements.

Writing prompts should specify the image and its context, requests for alt text options that describe the relevant information, guidance on how to determine what information is relevant, and recommendations for achieving conciseness while maintaining completeness.

Handling Decorative Images Correctly

Decorative images do not convey information and should be skipped by screen readers. This requires empty alt text, not missing alt text. The distinction matters.

Decorative image prompts should specify how to identify decorative images, guidance on implementing empty alt text correctly, explanation of why empty alt text (alt="") is different from missing alt text, and processes for auditing content to ensure decorative images are handled correctly.

Describing Complex Images Like Charts and Graphs

Charts and graphs convey complex information that cannot be fully captured in short alt text. They require both brief alt text and longer descriptions that convey the data.

Complex image prompts should request brief alt text that summarizes the chart’s key message, guidance on providing longer descriptions for detailed data, approaches for making charts accessible beyond alt text, and recommendations for linking charts to accessible data tables.

Generating Alt Text with AI Prompts

AI tools can generate alt text suggestions based on image analysis. The quality of suggestions depends on how specific and contextual your prompts are.

Generation prompts should specify the image, its context within your content, the audience for your content, requests for alt text options that vary in approach and length, and guidance on selecting the most appropriate option.

A generation prompt: “Generate alt text for a product photo on an e-commerce page. The image shows a customer wearing a blue denim jacket with silver zipper details, standing in an urban setting with brick buildings in the background. The jacket is the primary focus of the image. Generate three alt text options: one that focuses on the product details, one that focuses on the lifestyle context, and one that provides a balance of both. For each option, note whether it would be appropriate for this product context and why.”

Reviewing and Refining AI-Generated Alt Text

AI-generated alt text should be reviewed before publication. The review ensures accuracy, appropriateness, and alignment with accessibility standards.

Review prompts should specify what to check when reviewing AI-generated alt text, identification of common issues that require revision, guidance on when to override AI suggestions, and processes for improving alt text generation based on review findings.

Applying Alt Text Best Practices Across Content

Alt text quality should be consistent across all content. Systematic application of best practices ensures a uniformly accessible experience.

Application prompts should request approaches for ensuring alt text consistency across large content libraries, tools and processes for auditing existing content, recommendations for training content creators on alt text best practices, and processes for maintaining alt text quality over time.

Measuring Alt Text Quality

Quality metrics help ensure alt text meets accessibility standards and drives improvement over time.

Measurement prompts should specify the metrics for alt text quality assessment, approaches for auditing alt text quality across content, benchmarks for what represents acceptable alt text quality, and processes for using measurement to drive improvement.

Frequently Asked Questions

How long should alt text be? Alt text should be as concise as possible while conveying the necessary information. For most images, one to two sentences is sufficient. Complex images may require more detail, but avoid excessive length that becomes tedious for screen reader users.

Should alt text include “image of” or “photo of”? No. Screen readers already announce when something is an image. Adding “image of” or “photo of” is redundant. Simply describe what the image depicts.

What about images that contain text? Images that contain text should have alt text that includes the text shown in the image. The text should be reproduced exactly as it appears in the image.

How do I handle images I cannot describe well? If you genuinely cannot determine what an image shows or what information it conveys, consult with someone who knows. Accessibility requires that all meaningful images have meaningful alt text.

Conclusion

Alt text is essential for web accessibility, yet it is frequently neglected or implemented poorly. AI tools help content editors generate alt text that is specific, descriptive, and genuinely useful rather than generic filler.

Apply these prompts to your content workflow. Use AI to generate alt text suggestions, review them for accuracy and appropriateness, and implement alt text that serves all users. The resulting accessibility improvements benefit everyone while reducing the risk of accessibility complaints.