Everyday action item: make your images more accessible by adding alt text
Alternative text, or alt text, are words that describe an image or other graphic. Alt text helps people with low vision, and others who use assistive technology such as screen readers, understand what’s happening in the image. Taking this extra step improves your communication by making your information more accessible, and it signals to readers who use assistive technologies that you are making an effort to include them. Alt text on webpages can also replace an image file if the file fails to load, and it is indexed by search algorithms, which helps everyone find and engage with your content.
Alt text should concisely and accurately describe what is in the image so that the screen reader can communicate it to the user. Screen readers don’t get context clues, however, so it’s important for the writer to include both the content and the function of the image so it can be understood in the intended context. You can usually do this in one or two sentences; more complex figure descriptions may be better served in the surrounding text of the document or post. For more information about writing alt text, and to get some practice, take a look at the Poet Training Tool.
For applications we commonly use in STEM research and teaching, adding alt text is often quick and straightforward. Vanderbilt Student Access Services has a great help page for many different applications. Usually, you can right click an image to find the option to add alt text; sometimes you have to go into the Format or Settings menu. Here are the instructions for Microsoft Office documents, spreadsheets, and presentations, and for Adobe PDFs. Alt text is also available in Brightspace.
Online, you can add alt text to images on webpages and on social media. Facebook and Instagram automatically generate alt text, but writing your own is the best way to ensure it’s actually helpful. You can revise the alt text for your post using the Edit and Advanced Settings menus on Facebook and Instagram. Twitter does not automatically generate alt text, so readers who use screen readers will miss out on your content unless you manually add description. We’ll be doing our part on the @VanderbiltCDB feed and on the CDB website; we hope you’ll all join us!