Texas Tech University

Alternate Text for Images

Visual elements are essential to good design and help create beautiful and effective learning content. These visual elements should not be omitted for the sake of accessibility. Rather, alternate text should be used to describe all relevant visual elements for those using assistive technology. 

Alternate Text for Images

The purpose of the image is key when creating alternate text. You should describe the image the same way you would describe it to the audience, pointing out only the relevant parts of the image.

General Guidelines for Writing Alt Text

  1. Context is Key: The context of the image should determine what is mentioned in the description.
  2. Consider Your Audience: Use language appropriate for your audience's age, background knowledge, and purpose in viewing the image.
  3. Be Concise: Keep most image descriptions below 250 characters.
  4. Be Objective: Describe only what you see, not your interpretation of the image.
  5. General to Specific: Start with the big picture, then add specifics.
  6. Tone & Language: Use active verbs in the present tense. Use correct spelling and punctuation.

Extended guidelines for alternate text from DIAGRAM Center.

Add Alt Text in Microsoft Office 2016

To add alt text to a picture

  1. Click on the picture you want to add alt text for. Navigate to the "Format" tab and click on "Alt Text".
    Format Tab in Picture Tools in Microsoft Word with a box around the Alt Text button
  2. The Alt Text pane will appear on the right-hand side of the screen. Write the brief description of the image in the box provided. Or if the image is only decoration, check the box to indicate that the image is decorative.
    Alt Text Pane in Microsoft Office
  3. Note: If you choose to use the "Generate a description for me" option, be sure to review and edit the description as the auto-generated descriptions are frequently incorrect or insufficient.

Add Alt Text in Microsoft Office 2013

To add alt text to a picture

  1. Right-click on a picture or object and choose "Format Picture".
  2. In the Format Picture panel, choose "Layout & Properties", and then choose "Alt Text".
  3. Fill in the Description box, you can leave the Title box empty. 

Format Picture Sidebar in Word 2013 with circle around the "Layout & Properties" and the words "Add description here" in the Description box

Watch a video about creating alternative text.

Add Alt Text in Blackboard

To add alternative text in Blackboard

  1. From the Text Editor, navigate to the "Insert/Edit Image" Page.
  2. Enter your alternative text in the "Image Description" field.
    Insert/Edit Image screen in Blackboard with arrow pointing to the image description field
  3. Click "Insert".

Long Descriptions for Complex Images

Some images are more complex and need a longer description such as charts, graphs, infographics, etc. Alternative text for these types of images should not be (and sometimes cannot be) placed in an Alt Text box. Instead, a long description should be created and placed near the image.

Creating Long Descriptions

When writing long descriptions for complex images be sure to include all the information included in the image. This may take several paragraphs but is necessary for the user to fully understand the image. In some cases, a table can be used in a long description to convey data from a chart or graph.

Where to Place Long Descriptions

A link to the description, or the description itself, should be placed somewhere directly above or below the complex image. If linking, the long description could be placed at the bottom of the page, on its own separate page, or in an appendix. Any of these is fine as long as the link is descriptive and easy to find. In these cases, the alternative text for the image should also indicate where the long description of the image can be found.

Helpful Links

Guidelines for Describing STEM Images

DIAGRAM Center. A comprehensive resource for image descriptions

Online Accessibility at Texas Tech