Simple Alt Text Example 

The following is an example of simple alt text that describes a photo. Alt Text is embedded in the graphic and not displayed as a caption. 

This is an example of  the Alt Text embedded in the picture: The background shows a Lighthouse on top of a cliff facing the Pacific Ocean. In the foreground is a smaller green hill along the calm and blue/green ocean.  

Why is Alt Text Important? 

• For users with visual impairments, Alt Text can be read aloud by screen readers.  Note: if an image is complex a long description may be needed in addition to Alt Text. 
• Written descriptions can help users process complex visual information by presenting it in multiple ways. 
• Alt text is available to search engines, increasing a website’s search engine optimization. 
• It can be used for voice navigation on graphical links. 
• When images don’t load, alt text is displayed. This is particularly helpful when access to the internet is limited and a broken image is displayed. 

Additional Benefits of Alt Text 

• A written description of an image can help all users process more complex visual information by presenting it in multiple ways. 
• Alt text is available to search engines. This can help boost a website’s search engine optimization. 
• Alt text can be used for voice navigation on graphical links. 
• Alt text displays when images don’t load right away - for example, in areas of limited internet access when normally you would get a broken image like the one below: 

Figure 1 - Example of Broken Image

Alt Text Best Practices 

Alternative text should be both concise and meaningful to the listener. It conveys the purpose of an image, not every detail. Consider the following when writing alt text:

• Keep it short, if possible. Be concise with the description. 
• Consider the key elements of the image and the reason you included it in the document. 
• No need to include words like “image of” or “picture of.” 
• Consider the context and audience. What is their background? 
• If the image is also a link, the alt text should describe the link target. 
• If there is text in the image, include it in the alt text, if it is important information. 
• If the image is already described in the surrounding text, the alt text can be very short. 
• If an image is purely decorative, mark it as such (generally a check box is available for decorative). 

Automatic Alt Text 

In many cases, programs such as Blackboard, Microsoft Word, or PowerPoint, will automatically generate alt text for images, either using artificial intelligence, or inserting the filename or URL that the image originally came from. Automatically generated alt text is only a suggestion. It's important to check alt text manually to ensure that if offers a useful description. 

Resources 

• WebAIM – Alternative Text 
• Section 508.gov – What is Alternative Text?