Here’s why you should use alt text

The Grand Canyon with clouds in the sky with a setup explaining alt text

Sean Kugler is a digital accessibility analyst for NAU’s Office of Disability Resources.

Many of you have heard the term “alt text.” What is alt text? Alt is short for alternative. The purpose of alt text is to provide a textual alternative to the image you are using and why you are using it. You are creating as close to the same experience for all your viewers.  

Who reads alt text? 

Alt text is meant to be used by people who use screen readers or other assistive technology to interact with their phones and computers. Many of the individuals are blind or have low vision. It can also be used by people with slow internet connections or low bandwidth when pages are not fully loading. 

Other benefits of alt text

Are you familiar with SEO? SEO is search engine optimization. This means that the words you use in alt text are added as keywords that are used when people search the internet. Like hashtags, your alt text can bring more people to your post, blog or website. 

Do all images need alt text? 

Not all images require alt text. Some are purely “eye candy” and do not provide any meaning for your webpage/blog/flier. They are simply there to catch someone’s eye and their only purpose is decoration. In those cases, the image can be marked as artifact or decorative.  

Keys to effective alt text 

Alt text is about more than a visual description of the image you have chosen to post or share. It is about what you think is purposeful about the image. Pictures are worth a thousand words, which of those words is important to your message. Think about what you would add as alt text for the image below. 

Entrance to NAU's Old Main buildingHere are some options:

1. Photo of NAU’s Old Main building. 

2. Photo of NAU’s Old Main entrance. 

3. Photo of historic red brick building entrance with stairs. 

4. Photo of student walking down the stairs in front of Old Main. 

5. Photo of Rachel Kanyur walking down the stairs in front of Old Main. 

Considerations for choosing alt text include why you are using the image—what in the image is important for your message.  

Alt text for flowcharts, graphs, charts and diagrams 

When describing flowcharts, graphs, charts and diagrams, it is important to describe what is being conveyed visually. Think about a pie chart demonstrating the market share of computer operating systems. Convey the insights the chart displays:  

Pie chart that shows Windows own 65.79% of the market share, while OS X has 25.32%, Chrome OS has 3.45%, 3.08% are unknown, and Linux as 2.35% of the market shares.

Pie chart that shows Windows own 65.79% of the market share, while OS X has 25.32%, Chrome OS has 3.45%, 3.08% are unknown and Linux has 2.35% of the market shares. 

If you are using graphs that show trends, describe the trends. Remember the message you are conveying through the graph. 

Alt text in social media 

Many social media platforms now allow you to add alt text. Please add it as the platform allows, but also include the text in the post itself. This makes it accessible to everyone. 

Use those pics! 

Go take some pictures and be sure to describe them in the alt text. 

References and additional information:  

Alternative Text for complex Images 

Desktop Operating System Market Share USA 

Everything you need to know to write effective alt text 

Google Images best practices 

What is Alt Text and Why is it Important? 


NAU Communications