Type the alt text in the menu that pops up to the right. Use 150 characters or less.
Boats full of people in a small river surrounded by blooming Sakura Trees. Downtown Tokyo is in the background. (111 characters)
If the image is decorative, write the word Decorative as the alt text (do not check the box that says "Mark as decorative"). The reason for this is explained further on this page.
Examples of Good and Bad Alt Text for the Tokyo river Image above.
This example of Alt Text fails to describe all of the details in the image.
This example of Alt Text is much better. It describes many details in the image so that the reader has a better idea of what is in the picture.
Section 5.2: Labels on Charts and Graphs
Data labels are very important for accessibility purposes. If data labels are not present, then readers will have fewer queues to help them read the information. Charts, tables, and graphs can become completely inaccessible without their labels, so always add them.
To add data labels, click on your chart, and click the Chart Elements Plus sign in the top right corner. Choose which data labels you want to use and customize them so they are visible but does not distract from the chart itself.
This table does not have any data labels on it. A person who is color blind may have trouble knowing the differences between the sections and categories.
Section 5.3: Long Descriptions for Complex Images, Pie Charts, and Bar Graphs
When using complex images like pie charts or bar graphs, it is better to use a long description rather than Alt Text. Alt Text is meant to be brief, while long descriptions give you a bit more freedom to explain the image. There are many ways to create a long description including:
Describing the complex image in text below the image.
Adding a link below the complex image.
Providing the data from the image in text form.
Make sure the long description is visible to all users. Even if they are links, or buttons.
Additional Types of Long Descriptions
When you use complex images, you must describe it using Alt Text and have a longer description.
Section 5.4: Watermarks and Backgrounds
Watermarks and background images should not be used. They will interfere with peoples ability to read the page. Watermarks and backgrounds tend to be very distracting to most readers. It is best to use a background that does not interfere much at all with the text on the slide.
Section 5.5: Text Boxes, Shapes, and Other Floating Objects
PowerPoint differs from Word in one very significant way: floating objects are easy to navigate and make up the very nature of the entire deck. The title field in a slide, for instance, is a text box. However, unlike in Word, where navigating text boxes with a screen reader is tedious, in PowerPoint, a user just needs to tab around the slide and each object will be selected, announced, and the alt text (if present) will be read.
You do not need to add alt text to text boxes, since the contents are directly read by a screen reader, but you MUST add alt text to other non-text objects, including shapes and icons (and of course, images, graphs, charts, etc.).
Its better to not use any floating objects in PowerPoint. Floating objects are not part of a documents structure. When they are brought into an essay or article, they can disrupt the flow and make it very difficult to read. JAWS 18 and newer can read some floating objects at their anchor or insertion point. However, they cannot read text boxes (the alt text is not automatically read). JAWS users can also use Control>Shift>O to access a list of floating objects. The issue here though is that they can easily be read out of order or violate the flow of the text. NVDA can also read some floating objects in the drawing layer, but only if they are inline with the text.
Inline Objects are more accessible for readers. The only way you can use Floating Objects, is by making sure they are inline with the text. If this cannot be done, do not use Floating Objects.
How to make Text Boxes Accessible
Generally, screen readers cannot access the text box. Despite this, there are still ways of making a text box accessible to all readers.
Create a warning or alert to the reader that there are text boxes and how to access them.
Position Text Boxes inline with the text.
Text boxes should be given Alt Text.
To create a text box, use the following steps.
Go to the Insert Tab.
In the Illustrations Panel, click the Shapes Button.
Click Create Textbox in the upper left corner of the dropdown menu.
Create a Warning or Alert to the Reader that there are Text Boxes
Text Boxes should be given Alt Text
Section 5.6: Smart Art
In order for Smart Art to be accessible, only two rules must be followed.
The smart art has to be inline with the text.
You must provide an Alt Text for the smart art.
The Smart Art has to be Inline with the Text
The Smart Art must have an Alt Text
Section 5.7: Shapes
Shapes cannot be read by screen readers because it is considered to be floating content. Each screen reader treats shapes differently. NVDA announces the shape as “slash”, but does not read the alt text. JAWS announces the type of shape and the size, but does not read the alt text. VoiceOver automatically reads the alt text and announces that it is a shape, but not what shape. In short, there is no good way for shapes to be read yet. When creating shapes, follow these rules to make them more accessible.
Rule 1: The individual shapes may not be meaningful, but the overall drawing might be.
Rule 2: Provide Alt Text to only one of the objects.
Rule 3: Make the shape inline with the text. To do this, right click the shape, go to Wrap Text > In Line with Text.
Rule 4: It is always recommended to add Alt Text to a shape. To do this, right click the shape. Then click Edit Alt Text. In 100 characters or less, describe your shape.
Rule 5: For exporting to HTML and EPUB, take screenshots and supply alt text.
Rule 6: A user must be alerted to meaningful shapes in the document.
Section 5.8: Using a Series of Shapes
A series of the same shapes or images should be grouped. They should also be given alternative text and a long description.