Office of Inclusive Design

Alt-Text and Image Descriptions

Using alt-text for images in documents, presentations, and social media posts is a necessary part of making your materials accessible and inclusive. Individuals with vision impairments and those who use screen-readers will face barriers to fully understanding visual content without alt-text or image descriptions that describe the images used in your presentations, social media, or documents. This resource is meant to provide a guide for alt-text and captioning so you can make your content as accessible as possible.  

Making Effective Alt-text and Image Descriptions  

When writing alt-text or image descriptions for your content, use these guidelines to ensure effective and accurate descriptions: 

  • Be detailed but concise.  
  • Write out exactly what you see without adding too much fluff to your descriptions.  
  • Many screen-readers will cut-off alt text after around 125 characters, so staying concise is important.  
  • When describing an image, add directional cues (e.g., flower in the top left corner)  
  • Avoid starting descriptions with “an image of…” this takes up precious characters and can be redundant.  
  • You can describe the type of content (e.g., headshot, landscape, graphic, chart, etc.)  
  • Include any text that is part of the image in your description (e.g., black text that reads “Office of Inclusive Design” in the center of the graphic” 
  • Make sure to include colors in your descriptions  
  • Avoid making assumptions about race or ethnicity of individuals in images.  
  • You do not need to describe things that don’t add contextual information to the image. For example, it is unnecessary to write “page break in center of graphic”  

Alt-text and Captions for Social Media Posts  

  • Most social media platforms will have accessibility features that you can use to make your images automatically accessible.  


  • To access alt-text when posting go to accessibility>alt-text then write out a description of the content in the post. To be safe, also add this description to the bottom of your caption!  
  • If posting stories, videos, livestreams, etc. Please be sure to turn automatic captioning on for Deaf/hard of hearing viewers. 


  • Facebook automatically generates alt-text for images, but you should check to make sure the descriptions are accurate. To do so, click on your post and hold, then click “Edit Alt-Text.” Please also make sure to copy this alt-text to your caption as an image description. 


  • After adding image to tweet, click “+alt” button in the bottom right corner of image preview. 
  • A pop up will ask you if you’d like to add a description to your image(s), click “sure”. 

Alt-text and Image Descriptions in PDFs 

In Adobe Acrobat Pro: 

  • Open your PDF, click on the “Tags” option from the accessibility menu, click on the “Figure” option from the “Tags” menu. Add your alternative text to the designated textbox and click “close.”  

Without Adobe Acrobat Pro: 

  • If you are creating a PDF without access to Adobe Acrobat Pro, please include an image description below each image so screen-readers can still read out the description to the user.  

Alt-text and Image Descriptions in PowerPoint 

  • In PowerPoint, select the image you wish to add alt-text to then select the “Picture Format” option. Next, select the “Alt-Text” option in the ribbon. You can edit the alt-text by right-clicking the image and selecting “Edit Alt Text” in the menu that pops up.  
  • If you are presenting the slides live, please also describe the image verbally during your presentation.  

If you need any additional support or have any questions alt-text, image descriptions or social media best practices please contact the Office of Inclusive Design (