Best practices for adding Alt text to images in documents

Imagine you’re looking at a document filled with images that explain key concepts or provide critical data—but you can’t see them. For millions of people who are blind or visually impaired, this is a reality. That’s why alt text for images is such a powerful tool. It turns visual content into meaningful descriptions that everyone can access, regardless of ability.

Alt text, or “alternative text,” isn’t just a technical detail; it’s a key part of making documents and websites more inclusive. Whether you’re creating PDFs, Word documents, or online content, knowing how to write alt tags effectively ensures your visuals are accessible to all.

This blog will guide you through everything you need to know about alt text: what it is, why it matters, best practices for writing it, and common mistakes to avoid. We’ll also share resources to help you improve accessibility in your documents.

What Is Alt Text, and Why Is It Important?

What Is Alt Text?

Alt text is a short description assigned to an image, allowing screen readers to “read” the image aloud to users who cannot see it. Essentially, it paints a word picture that captures the meaning of the visual content.

Why Was Alt Text Created?

Alt text was initially designed to help when images failed to load due to slow internet connections, but its purpose has evolved. Today, it plays a crucial role in making digital content more accessible to people with disabilities.

Why Is Alt Text Important?

• Empowers Users with Disabilities: Alt text ensures that people who are blind or visually impaired can understand the meaning behind images in a document.
• Improves SEO: Search engines use alt text to index images, which can improve the visibility of your content online.
• Legal Compliance: Many laws and standards, like the ADA and WCAG, require the use of alt text to ensure accessibility.

In short, alt text for images makes your documents more inclusive while also enhancing their discoverability.

Best Practices for Writing Alt Text

Writing effective alt text is an art that balances clarity, brevity, and context. Here are some best practices for alt text, complete with good alt text examples to guide you:

1. Be Descriptive and Clear

   Alt text should describe what the image shows, focusing on its main subject and purpose. Avoid vague language.
   Example:

   • Image: A woman holding a cup of coffee while sitting in a café.
   • Good Alt Text Example: “Woman sitting in a café, holding a steaming cup of coffee.”
   • Poor Alt Text Example: “A woman.”

2. Focus on Context and Purpose

   Think about why the image is included in the document. Your alt text should highlight the most relevant details based on the image’s purpose.
   Example:

   • Image: A chart showing sales growth.
   • Alt Text: “Bar chart showing monthly sales growth, increasing from $5,000 in January to $12,000 in December.”

3. Skip Redundant Phrases

   Avoid starting with “Image of” or “Picture of.” Screen readers already announce it’s an image, so get straight to the description.
   Example:

   • Image: A dog running in a park.
   • Good Alt Text Example: “Golden retriever running through a grassy park.”
   • Poor Alt Text Example: “Image of a golden retriever in a park.”

4. Keep It Concise

   Alt text should be short and to the point. Aim for one to two sentences that capture the essence of the image.

5. Handle Complex Images Thoughtfully

   For charts, graphs, or infographics, summarize the key information. If necessary, add more details in the surrounding text.
   Example:

   • Image: A pie chart showing market share.
   • Alt Text: “Pie chart showing market share: Company A 50%, Company B 30%, others 20%.”

6. Mark Decorative Images as Such

   If an image is purely decorative and doesn’t add value to the content, mark it as decorative. This prevents screen readers from announcing unnecessary details.

Common Mistakes to Avoid

Even small missteps in adding alt texts to images can significantly impact accessibility. Here are some common mistakes and how to avoid them:

1. Missing Alt Text

   Without alt text, users relying on screen readers are left guessing about the image’s content.

2. Being Too Vague

   Descriptions like “Image of a person” or “Graph” don’t help users understand the image’s purpose. Be specific and relevant.
   Example:

   • Image: A student raising their hand in a classroom.
   • Good Alt Text Example: “Student raising their hand in a classroom with a teacher at the front.”
   • Poor Alt Text Example: “Classroom scene.”

3. Including Unnecessary Details

   Overloading your alt text with irrelevant details can overwhelm users. Stick to what’s essential.

4. Writing for SEO, Not Accessibility

   While keywords can improve your content’s visibility, stuffing them into alt text makes it less user-friendly. Prioritize clarity over keyword density.

5. Forgetting to Label Decorative Images

   Not marking decorative images as such can disrupt the flow for users relying on screen readers.

Tools and Resources for Writing Alt Text

Feeling overwhelmed? You don’t have to do this alone! Tools like AccessibleDocs.ai can simplify the process, ensuring your alt text is both effective and compliant with accessibility standards.

Conclusion

Alt text might seem like a small detail, but its impact is enormous. By following these alt text guidelines, you can make your documents and websites more inclusive, accessible, and user-friendly.

Remember, writing alt text isn’t just about meeting legal requirements—it’s about creating a world where everyone can participate and feel included. With tools like AccessibleDocs.ai you will learn how it works, and you can take the guesswork out of accessibility and focus on what really matters: making a difference.

So why wait? Start implementing these tips today, and let’s work together to build a more inclusive digital space, one image at a time.