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Digital Accessibility

Alternative Text

Alt text (or alternative text) is a description of an image that allows those who cannot see the image to access the same visual information as those who can.

Why Do We Need Alt Text?

Images usually communicate important visual information. If someone can't see an image for any reason, alt text gives them a way to access that information.

Alt text is crucial for people with vision-related disabilities.

Without it, your audience who have disabilities like low vision or blindness have no way of obtaining the information communicated by your visuals.

Anyone might be in a situation where they can't see images.

If someone's internet connection is slow or their computer settings disable images from loading, alt text can help them access image information if it's written correctly.


Alt text must be considered for all images.

Almost every image you publish in a digital context will require alt text. Even decorative images that add no additional visual information must be marked so that a screen reader will skip them. 

Examples of Images That Need Alt Text

This is not an exhaustive list, but these are common types of images you'll need to describe with alt text to describe. 

  • Website Visuals
  • Social Media Posts
  • Infographics
  • Logos
  • Headshots


How to Write Alt Text

Writing effective alt text can seem difficult at first, but if you follow these steps to analyze your images and understand what they're communicating, it will become easier. 

Step-by-Step Instructions »

Close-up images of individuals present their own accessibility concerns, but it's easy to write alt text for headshots if you keep some basics in mind.

Writing Alt Text for Headshots »

In addition to any text, you'll want to include the context and layout of your image. Here are some helpful tips for describing graphics.

Writing Alt Text for Infographic Images »

Logos and marks may seem self-explanatory, but they still communicate information and require alt text. Here are some guidelines for describing logos as well as standard alt text for USC logos and marks.

Writing Alt Text for Logos »

When communicating complex information, it's common to display what you're trying to convey in terms of a chart, diagram or other visual representation. Those with certain types of disabilities will not be able to interact with this information in the format of a visual, but you can make it accessible to them in a couple of different ways.

Writing Alt Text for Charts & Diagrams »

In the rare instance where an image adds absolutely no additional information to the screen's content, you can mark it as "decorative" and skip writing alt text. 

Handling Decorative Images »

All images that also serve as a link must have alt text, even if they would otherwise be considered decorative.

Writing Alt Text for Linked Images »

Finding Images with Pre-Written Alt Text

Some royalty-free stock photo sites provide pre-written alt text. You will still need to check that the alt text is accurate and descriptive before using it. 

Unsplash in particular does a good job providing ready-to-go alt text for images.


Adding Alt Text in Specific Platforms

The way you'll add alt text to your images will depend on the tool or platform you're using to publish digital content.

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