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Ally: ALT Descriptions for Images

Images can be a great way to engage your learners with different modes of learning, and can help communicate complex ideas to students. For students with visual impairments, image descriptions that explain the content of an image are crucial for their learning. For all students, text descriptions can provide deeper context to aid their comprehension.

Ally checks for image descriptions anywhere there is an image. This includes image files and files that include images. For example, a document or presentation.

ALT - Alternative text: word phrase that is inserted in the HTML to describe the image for people who are unable to see the image. 

tip Make sure to read the tips for fixing content that will copy into your future courses. 

What is Ally | WorkshopsUsing Ally | Ally Copy Tips | Anthology Ally Support


Fixing ALT Descriptions

Fix Canvas Pages  |  Fix Canvas Images in Ally   |  Fix Other Files  |  How to Write Descriptions


1) Using Ally to Fix ALT Descriptions on Canvas Pages

Once you provide an alternative description for an image through Ally in a Canvas Page, the description will change to a Green indicator “dial”. The description added through Ally will get pushed back into the Canvas content directly so that it can be stored by Canvas and made available to your students. This ALT description is not saved in Canvas and can be copied into future courses. 

From the Canvas Page 

  1. Look for a red or orange Accessibility Score - Dial (bottom left of image).
  2. In Canvas, click on the Pages course menu (left). If you have a HOME page, you will need to click on the View All Pages button (top left). 
  3. Use Canvas' Rich Content Editor to fix the page, Click on the Edit button on the top right of the Page.
     Pages, Edit and the image dial
  4. Click on the image within the page, then select Image Options
     Image Options button
  5. Add the ALT Description in the (A) ALT Text box OR click on (B) Decorative Image box (if the image is decorative). Note: this is an example of a "decorative" image on a page. 
    Canvas Image Options
  6. Scroll down and choose the Done button. 
  7. At the bottom of the Page, click on the Save button (bottom right). 

    - Video tutorialAdd ALT Text to Images in Canvas


2) Using Ally to Fix ALT Descriptions for Images NOT in Pages

Some of the images are not located on Pages. Maybe they are in an assignment description, discussion instructions or on a quiz. You may not want to add ALT to a quiz image if the question is about the image, in this case you can make it "decorative", but for the other images you will need to add an ALT description. Fixing the ALT tag within Ally's Accessibility Report tools will be saved and copy into your future Canvas courses. 

From the Ally, Accessibility Report

  1. Click on the Accessibility Report course menu (left).
  2. Click on the View button under All Course Content.
    Ally Report image 
  3. Look for the images (png, jpg, gif), click on the Score - Dial on the right of the image. 
    Ally score for image
  4. Add the ALT Description in the (A) Add image description box OR click on (B) Indicate image is Decorative button (if the image is decorative). Note: this is an example of a "decorative" image on a page.

    ALT descriptions in ally
  5. Click on the Close button.  

    - Video TutorialUsing Ally to Fix Course Content


3) Using Other Applications to Fix ALT Descriptions for Images

Files (PDF, DOC, PPT) added into Canvas also have images. It is best to fix those ALT Descriptions within the applications the files were created.


Workshops, Online Courses & Web Resources 

Writing Good Descriptions

ALT tag descriptions should be short - less than 100 characters. This description is extremely important when students come across an image that has become suddenly unavailable and when students who rely on a text-to-speech or screen reader program to navigate the web access your course content. In the former case, the alt text is visible to any sighted person. In the latter case, the alt text is read aloud or translated to braille. If you need more than 100 characters to describe this image via the ALT tag, add the instructional text within the page.

Follow these best practices to write good alternative text descriptions for your images:

  • Describe the image based on the page context. Convey the full meaning of the image. 
  • Avoid saying "image of" or "picture of". Screen readers automatically announce images as images.
  • Be concise.
  • Write narratives for complex images like infographics. Put this narrative on the page immediately following the infographic. Include an anchor link at the top of the page to view the text alternative. See an example of an infographic with a text alternative.
  • Avoid images of text. If you can't avoid it, copy the text into the alternative description.
  • Say something new. Don't repeat alternative descriptions on the same page. Don't repeat what is already said on the page.
  • Identify images that don't represent relevant content as decorative.

What is a decorative image?

An image is decorative when it doesn't add to the information on the page. For example, art work used to separate topics or a photo of someone on the phone when discussing communication skills.

They are valuable in their visual appeal but may not need to be read by screen readers.

tip Create Accessible Files that Copy into Future Course Shells

We have been given a message from Ally to remind users that while fixing your files with the Ally Accessibility Checker does create accessible files in your current courses… it does NOT copy as an accessible file into your other Canvas shells


  • Do not use the Files menu to fix images - ALT descriptions. These do not copy to future courses. Please use the Accessibility Report tools or the Canvas Page tools to add ALT descriptions. 


Anthology Ally Support


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