Adding Alt Text in PowerPoint

How to add Alt Text

  1. Select the Object:

    • Click on the image, chart, SmartArt, shape, or other object you want to add alt text to.

  2. Open the Alt Text Pane:

    • Right-click the object and select "Edit Alt Text", or
    • Go to the "Picture Format" or "Shape Format" tab on the ribbon, and click "Alt Text" in the Accessibility group.

  3. Enter a Description:

    • Write a concise and descriptive explanation of the object in the text box under "Description".
    • Leave the "Title" field empty unless your organization has specific guidelines for its use.

  4. Mark as Decorative (If Applicable):

    • If the object is purely decorative and does not convey meaningful information, check the box labeled "Mark as decorative". This tells screen readers to ignore the object.

Best Practices for Writing Alt Text

Be Concise:

  • Aim for 1–2 sentences. Describe only the essential details needed to understand the image's purpose.

Context Matters:

  • Tailor the description to the slide's content. For example, if an image is illustrating a concept already explained in text, the alt text can be simpler.

Avoid Redundancy:

  • Do not repeat information already present in the slide text.

Exclude "Image of" or "Picture of":

  • Screen readers already announce the type of object, so this information is unnecessary.

Describe Complex Images Separately:

  • For charts or diagrams, describe the key takeaway rather than every detail.
  • If the image is very complex, consider adding a detailed description in the speaker notes or providing a handout with additional information.

Examples of Alt Text

  • Image: A photo of a team brainstorming around a whiteboard.

    • Alt Text: "A group of five colleagues collaborating at a whiteboard, discussing strategies for a new project."

  • Chart: A bar graph showing sales growth over three years.

    • Alt Text: "Bar chart showing steady sales growth from 2020 to 2022, with revenue increasing by 10% each year."

  • Decorative Image: A decorative border or background.

    • Mark as decorative.

Checking Alt Text Accessibility

Use the Accessibility Checker:

  • Go to "Review > Check Accessibility".

    • This tool identifies any objects missing alt text and provides suggestions.

Test with Screen Readers:

  • Preview your presentation using a screen reader (e.g., NVDA or JAWS) to ensure the alt text provides meaningful descriptions.