Text Equivalents
In this section:
Text Equivalents
Assistive technologies employalternative text (alt text) attached to images to inform users of the context and purpose of images and visual elements. Alt text is a text alternative to non-text content to ensure all users can access information.
To add alt text in Office desktop programs:
- Right-click on an image and select Edit Alt Text…
- Enter a description in the dialogue box.
- If a graphic is purely decorative, check Mark as Decorative.
To add alt text in Office online programs:
- Select the image
- Navigate to the Picture tab
- Select Alt Text and enter your description in the Title field.
- If the image is purely decorative, leave the Title field blank.
The Office Accessibility Checker will flag images that need alternative text. Do not rely on the automatically generated alt text; it is rarely very useful. In the Accessibility pane, Missing alternative text will appear as an error. You can select the drop-down menu and choose Add a description.
Learn more about alternative text.
- Alt text must be attached to all visuals (images, graphs, diagrams, tables, charts, etc).
- Effective alt text provides content and function information to screen reader users. If the visual contains content, the alt text should convey that information in text form.
- Images may be included for decorative purposes as well; however they must be marked as such (“ “ entered in Alt text field is best practice, if no ‘mark as decorative’ or similar option is available).
- Avoid including “image of” or “graphic of” in alt text descriptions. Screen readers will inform the user of an image then read the alt text.
- Alt text should not be a repeat of an adjacent caption. Screen reader software will read both the alt text and the caption. Make each unique with the alt text providing information a sighted user infers from the image.
- Alt text descriptions should be less than 150 characters and no more than two short sentences with proper punctuation. A longer description may be necessary and can be provided by an alternate format (in the case of a complex diagram) or additional text below the image.
Review the chapter on Images and Alt Text for more information.
Add alternative text to simple charts but also include table data for complex charts and data sets. The best practice is to include table data adjacent to the chart, but linking to the data elsewhere in the document is also an effective method. Ensure the link text explains the destination.
Captions and Transcripts
Ensure embedded media has text equivalents. Videos must have closed captions, and audio must have a transcript.
To add captions to a video in PowerPoint, they must be in .VTT format (3Play Media offers a free .SRT to .VTT conversion tool).
To add a .VTT caption file:
- Navigate to the slide with the video and select the video
- Via the Playback tab, click Insert Captions, and select Insert Captions
- Select the caption file and click Insert
Images and Graphics
Apart from adding effective alt text to images, there are a few additional considerations for visual elements in PowerPoint presentations.
Take note of groups of images:
Hyperlink Text
Create meaningful hyperlink text.
- Avoid vague instructions like “see,” or “click here,” or “read more.”
- Not only are those not helpful out of context, but self-describing links may help you locate your resource if the URL changes
- Do not paste URLs as hyperlink text
- If URLs must be included, provide self-describing hyperlink text and format URLs as normal text with no link attached.
- Use default link styling (blue, underlined text)
To add links in PowerPoint:
- Select the text you want to link
- Right-click and select Hyperlink or press Control (Command on macOS) and K
- Change the Text to Display text if necessary
- Paste the destination URL in the Address box
More information on hyperlink text in PowerPoint can be found here.
Alternative text is a text equivalent of graphics in a document or webpage. Alternative text is coded to be hidden visually, but read to a screen reader user.
Information presented in a grid format of rows and columns, generally to show a relationship between sets of set
A text equivalent of audio content in a video, displayed synchronously. Closed captions are toggled on or off by viewers, as opposed to open captions that are burned into the video and always displayed.
Transcription is the process of converting audio into written text. A transcript is a written record of all audio in media. Captions are synced to the content.
The HTML attribute (alt='' '') used in HTML documents to specify alternative text that is to be rendered when the element to which it is applied cannot be rendered. It is used by "screen reader" software so that a person who is listening to the content of a webpage (for instance, a person who is blind) can interact with this element.
Also known as a link, a hyperlink directs users to a different portion of a document or page, or an entirely different document or page, once clicked or tapped by users.
