Provide a brief description that communicates the purpose or key content of the image.
7 Core Skills: Images & Alt Text
Images can add meaning and visual interest to your content, but not everyone can see them. Alternative text (alt text) ensures that people who use assistive technology can understand what an image conveys.
What Is Image Alt Text?
Alt text is a short description added to an image that communicates its purpose or meaning. Screen readers read this text aloud so users who cannot see the image can understand its content.
Alt text should reflect why the image is included. It does not need to describe every visual detail, but only what is important in context.
Why Is Image Alt Text Important for Accessibility?
People who are blind or have low vision rely on screen readers to access digital content. Without alt text, images may be skipped entirely or announced without useful information.
Clear alt text ensures that important visual content is not lost and that users can fully understand the message being conveyed.
Providing meaningful alt text improves accessibility, usability, and overall communication for everyone.
Top 3 Ways to Get Started
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Add alt text to informative images
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Keep descriptions concise and meaningful
Focus on what matters in context rather than describing every visual detail. There is no need to use the words like "image of..." in your description.
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Avoid using images to display important text
If text is embedded in an image, users may miss it. Use real text whenever possible.
What Does Good Alt Text Look Like?
Effective alt text is:
- Brief and clear
- Relevant to the surrounding content
- Focused on the purpose of the image
- Written without phrases like “image of” or file names
Good Example
If an image shows students working in a lab:
- "Students conduct experiments in a chemistry lab."
Bad Example
Image shows students working in a lab:
- Image_1234.jpg
- Picture of students.
The right description depends on why the image is included.
Common Mistakes to Avoid
- Leaving alt text blank for meaningful images
- Writing descriptions that are too long or overly detailed
- Repeating nearby text instead of describing the image
- Including file names or phrases like “image of”
- Embedding important text within images
Thoughtful alt text ensures visual information is not lost.
Most common tools include features to create alternative text for images:
- Microsoft Word and PowerPoint – alt text options available in image formatting
- Canvas – image settings include alt text field in text editor
- Web editors and CMS platforms – alt text required when you upload an image
- Accessibility checkers – available in nearly all platforms and often flag missing alt text
Learn more about image alt text for accessibility:
- WCAG 2.1 Success Criterion 1.1.1 – Non-text Content
- WebAIM: Alternative Text
- W3C Alt Decision Tree
- Microsoft Accessibility: Add Alternative Text to Images
Try this quick check on your own content:
- Open a document, presentation, or webpage you created.
- Select an image and review the alt text.
- Add or revise descriptions where needed.
Adding alt text is a small step that makes a big difference.