Better AI Image Descriptions for Screen Readers

Updated 7 November 2026 · Standard formula, shown below

This guide shows you how to write or generate image descriptions that work well with screen readers, making your content more accessible to people who are blind or have low vision. You’ll learn the principles behind good alt text, how to use AI tools effectively, and how to refine the output for accuracy and clarity. No special software is required—just a text editor and access to an AI image description tool if you choose to use one.

What You’ll Need

An image file (JPG, PNG, GIF, etc.) you want to describe.
A text editor or the content management system where you’ll add the description.
Optional: An AI tool that can generate image descriptions (e.g., a vision-capable chatbot, or an image captioning service).
Basic knowledge of the image’s context (what it’s for, where it appears).

Step-by-Step

Determine the image’s purpose. Before writing anything, ask: Is this image informative (charts, diagrams, photos that convey data), functional (buttons, icons), or decorative (purely aesthetic)? The purpose dictates the type of description you need. Informative images need detailed alt text; functional images need to describe the action; decorative images can have empty alt text (alt=””).
Write a draft description yourself. Start by writing a concise, objective description of what’s in the image. Include the main subject, any text visible, and the context that matters. For example, for a photo of a dog, write “A golden retriever sitting on a grassy lawn, holding a red ball in its mouth.” Avoid subjective language like “beautiful” or “cute” unless it’s essential to the meaning.
If using an AI tool, provide a clear prompt. When you use an AI image description generator, give it context. Instead of just uploading the image, say: “Describe this image for a screen reader user. Focus on the key elements: who/what is in the image, the setting, any text, and the overall scene. Be objective and concise.” You can also specify the desired length (e.g., “in 1-2 sentences”).
Review and refine the AI output. AI descriptions are often too verbose or miss important details. Edit the generated text to:
Keep it concise but complete. Aim for 1-3 sentences for most images. Include only what’s relevant. For complex charts or diagrams, you may need a longer description or a separate data table. For decorative images, use empty alt text so screen readers skip them entirely.
Use proper punctuation and spacing. Screen readers pause at periods and commas, so use them naturally. Avoid abbreviations that might be read aloud incorrectly (e.g., write “doctor” instead of “Dr.” unless it’s a title).
Test the description. If possible, use a screen reader (like NVDA, VoiceOver, or TalkBack) to listen to your description. This helps you catch awkward phrasing or missing context. If you can’t, read it aloud yourself—if it sounds choppy, revise.
Place the description correctly. In HTML, use the alt attribute for images. In a CMS, there’s usually a field labeled “Alt Text” or “Description.” Never put the description in the surrounding text as a substitute; screen readers will read both, causing repetition.

Common Mistakes

Using “image of” or “picture of”—Screen readers already announce that it’s an image, so it’s redundant.
Describing every detail—Including irrelevant background objects makes the description long and hard to follow. Focus on what matters for understanding the content.
Ignoring text within the image—If the image contains important text (like a sign or a screenshot), include that text verbatim in the description.
Writing vague descriptions—”A person” is less helpful than “A woman in a lab coat holding a test tube.” Be specific when possible.
Forgetting to mark decorative images as empty—If you leave alt text blank for a decorative image, screen readers may read the filename, which is confusing.
Over-relying on AI without checking—AI can hallucinate details or miss context. Always review and edit.

Tips

Use the image’s filename as a hint. If the file is named “sales-chart-2024.png,” you know it’s a chart about sales data.
Consider the surrounding content. If the image is in a paragraph about a product, you don’t need to repeat the product name in the alt text.
For complex images, provide a short alt text and a longer description elsewhere. You can use the longdesc attribute or link to a separate page with a full description.
Keep a consistent style. Use the same tense and level of detail across your site for a smoother experience.
Use AI as a starting point, not the final word. Generate a description, then edit it to match the specific context of your page.

Troubleshooting

The AI description is too long. Ask the AI to “summarize in one sentence” or manually cut out non-essential details.
The AI description is inaccurate. Re-upload the image with a more specific prompt, or describe the image yourself based on what you see.
Screen reader reads the filename instead of alt text. This happens when the alt attribute is missing or empty. Ensure you’ve added alt text in the HTML or CMS field.
Screen reader reads the description twice. You may have both an alt attribute and a caption. Remove one or make the caption different from the alt text.
You’re not sure if an image is decorative. Ask: Does it add meaning that isn’t in the text? If no, treat it as decorative and use empty alt.

Frequently Asked Questions

What is the ideal length for an image description?

For most images, 1-3 sentences is ideal. If you need more, consider whether the image is too complex and if a separate data table or long description would be better.

Should I describe colors in an image?

Only if the color is important to the meaning. For example, in a chart showing sales by region, colors are key. In a photo of a sunset, saying “orange and pink sky” is fine, but don’t list every color.

Can I use emojis in alt text?

Screen readers will read emoji descriptions aloud (e.g., “smiling face with heart-eyes”). Use them sparingly and only if they convey meaning.

How do I handle images with text in them, like memes?

Include the text verbatim in the alt text. For example, for a meme with text “When you finally fix the bug,” write that text in the description.

Is it okay to leave alt text empty for decorative images?

Yes, use alt="" (empty) so screen readers skip it entirely. This is the recommended practice.

What if I don’t have access to a screen reader to test?

You can use browser extensions that simulate screen readers, or simply read your description aloud to see if it flows naturally. Also, many online accessibility checkers will flag missing alt text.

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