“Alternative text” provides context for visual media that can be read aloud or described using assistive technology like a screen reader. Alternative text should be concise, usually limited to 125 characters (including spaces), and should describe the purpose or function of the graphic within the context of the document’s content.

Even if you’ve never had a blind or visually impaired student in your class, alternative text can be extremely helpful.

General Approach:

If you’ve ever had the experience of trying to describe something visual over the phone, you already have the basics of writing alternative text down. Think about when you’ve had to describe where an object should be in your house, directions to reach that obscure hiking trail, the very specific shirt you need washed, that fancy coffee mug you accidentally left behind in a hotel, etc. I use this same concept when writing alternative text. I start thinking about everything the person on the other side of the phone might need to know. I need to tell that person what the page is about, what images are on the page, and why they are there. By the time I’ve finished this thought work, I usually have a good idea of what type of alternative text I need to write and which images I’ll be focusing the majority of my energy on describing. 

Example Image:

Let’s take a look at the image below of elephants huddled together.

The context of how the image is used is going to help us understand what alternative text we need to write.

Decorative Image

Context: I’ve used this image to create a banner to add some color to my content page that describes common themes in African Folklore for my mythology class. The banner has no text; its purpose is to provide a visual break in the page to help students visually navigate through the concepts.

Extracting Meaning: The image is not providing information on the page. It might be decorative, but let’s be sure. If we replaced this image with another random image, would it change the student’s understanding of the content? For example, if I changed this image to one of a pack of lions, or of a famous African art piece, would that communicate a different idea to students? The answer here is no. While the image aligns with the broad topic of the page (Africa), it’s decorative in nature. I could remove the image, and students would have the same understanding of the topic.

Alternative Text: None. 

Justification: It’s best practice not to include alternative text for decorative images. However, you can include alternative text if you feel like it would enhance the student experience. One word of caution is that you need to determine if adding alternative text to a decorative image will make the page easier to read or more difficult. As the student is listening to the content being read aloud, would pausing to describe “a decorative banner with African Elephants” be distracting? There are very few cases when a decorative image would need to be described, but it’s always worth considering.

Literal Use: Using the image as an exact representation of the thing or idea

Context: I’m including some fun facts about myself on the “About Your Instructor” page of my course. I might include this image in a group of images under the heading “My Favorite Things”. In this way, the image is meant to identify my favorite animal as an elephant. 

Extracting Meaning: In this case, the most important part of the image is that it depicts Elephants. How many, their position, environment, etc, is not relevant. If I were to describe the image to someone who could not see my screen, I would simply tell them that I see a “picture of elephants”. 

Alternative Text: “Elephants”

Note: I don’t need to include “Image of” as the screen reader will let the reader know it’s an image before reading the alternative text.

Justification: Short and sweet, this will tell someone who cannot see the screen everything they need to know about the image and why it’s there. Remember, the header for this section says “My Favorite Things”, providing additional context of why this image is here. There’s no one way to write alternative text. I can always include more context, such as “a group of adult and baby African elephants standing together”, but this might cause confusion… am I making a distinction between Asian and African Elephants as my favorite? Is it important to know the age groups of the Elephants? Or, is the reason for having the image on the page (liking Elephants), explanation enough? 

Illustrative Use: Using the image as a representation of a concept

Context: This image of elephants is included in my women’s studies class on a page talking about the core concepts of a matriarchal society. In this particular section of text, I describe the way older elephants will circle young or injured elephants when they are faced with danger, demonstrating a defensive strategy when addressing conflict.

Extracting Meaning: The image could not be replaced with another animal group, as the text very specifically describes elephants, meaning this is not a decorative image. The behavior, as expressed through body language, in this image, is very important to illustrate the point in the text. It’s going to need to be described in detail to make sure students who can’t see the image are able to learn from it.

Alternative Text:

Option 1: Six elephants standing near the edge of the water. The three older elephants are turned away from the three younger elephants in a protective stance. 

Option 2: Adult Elephants standing with their backs to a group of younger elephants, demonstrating the described behavior of Elephants protecting their young.

Justification: Neither option is wrong. Option 1 focuses on what the image looks like, while Option 2 focuses on not only what the image depicts, but also how it is relevant to the content. Sometimes it’s better to include context for students who might miss the connection of the image to the concept. It can also be helpful if the order of the page means that the image would be described before the written content (or the written content might move to another idea before the image is described). Never be afraid to experiment with a screen reader to experience reading order!

Illustrative Use: Describing a highly detailed image

Context: I’m teaching a photography class, and this image is included as an example of framing. I want to talk about focus and using shape to create a visual path for the eyes.

Extracting Meaning: Because sight lies on a spectrum, it’s entirely possible a student who has a visual impairment could take my class. So I need to make sure a student who has a visual impairment can experience my class and have a similar learning experience to a visually able student. This image illustrates a core concept of the class, so my alternative text is going to need to pull from those concepts to talk not only about what the image depicts, but also how it is depicted, using context from the page’s content.

Alternative Text: A group of elephants gathered at a watering hole. The group forms a cluster around the smallest baby elephant near the center, drawing the viewer’s eye toward it as the focal point. The larger elephants are facing away from the smaller elephants, who are just left of center. The curved line of the adult elephant’s trunk on the right leads the eye toward a body of water, creating a natural visual path that leads back to the group. The repeating rounded shapes of the elephants’ bodies guide the gaze across the image, reinforcing the sense of unity and directing focus to the central subject.

Justification: That’s a lot more than 125 characters! But for this context, we need to be very detailed and clear about what the image is depicting and what the students should learn from looking at the image. We will likely use something like option 1 of the previous example to describe the image, and this longer description would be used as an image caption. After all, our visually able students would likely benefit from this level of description! If I’m not able to see the entire image or make out certain details, this long captioned description might help me (literally) fill in the blanks. 

Wrapping it Up

With that, you now have some basic questions and strategies for tackling the images in your courses and content. Remember, there is no “right” way of describing an image. Do your best, think through the reasons you chose the image, and what students should learn from it. This process can be fun… or at least I think so!

Next time, we’ll talk about using alternative text to describe images used for assessment! Read about it now: Alt Text and Assessment Article

Need Help?

For those who are comfortable with computers, there are AI-powered alternative text generators that can help you describe those complex images, charts, and tables. Like this one from ASU.

For those who prefer a human approach, the CTLE can help you develop strategies to break down and describe complex images. Feel free to stop by our Open Lab M-F 9 am – 3 pm or pop by to see us in person!