The Complete Guide to Alt Text for SEO in 2024

Alt text (alternative text) isn’t just important for accessibility — it also plays a key role in image SEO. Modern search engines are much better at understanding image context, which makes writing proper alt text essential for improving visibility in search results.

What Is Alt Text and Why Does It Matter for SEO?

Alt text is a short description added to an image that helps both users and search engines understand what the image represents.

• Search engine understanding: Helps Google and other search engines interpret image content
• Image search visibility: Improves chances of appearing in Google Images and visual search results
• Accessibility: Allows screen readers to describe images to visually impaired users
• Fallback text: Displays if an image fails to load

Alt Text Best Practices for SEO

1. Be Descriptive and Specific

Write short, clear descriptions that accurately explain what’s happening in the image.

2. Include Keywords Naturally

If relevant, include your target keyword — but only when it fits naturally.

3. Keep Alt Text Short

Aim to keep alt text under 125 characters so screen readers can read it clearly without cutting it off.

4. Match the Image Purpose

Write alt text based on how the image is used on the page:

• Informational images: Describe what the image shows
• Decorative images: Use empty alt="" when the image adds no meaning
• Functional images: Describe the action (for example, “Submit form”)
• Product images: Include brand, product name, color, and key details

Common Alt Text SEO Mistakes

Key Takeaways

• ✅ Write clear, descriptive alt text
• ✅ Keep it short and natural
• ✅ Use keywords only when relevant
• ✅ Match the image’s purpose
• ✅ Review and improve older content