Write Effective Alternative Texts

Alternative text (Alt Text) is a textual description of a visual in a document or website that helps users of screen readers understand the content of the images. When using a screen reader to view the document or save it to a file format, such as HTML or DAISY (Digital Accessible Information System), alt text appears when you move the pointer over an image in most browsers.

Here we explain how to add alt text in Word, Excel, and Power Point to a shape, picture, chart, table, SmartArt graphic, or other object, and show how to make the Alt Text command always available.

You can add the Alt Text command to the Quick Access Toolbar to create a shortcut to it.

STEP 1 In the upper left corner, above the ribbon, click Customise Quick Access Toolbar.

STEP 2 Click More Commands.

STEP 3 Click Commands Not on the Ribbon.

STEP 4 Click Alt Text, then Add.

To use the Alt Text command on the Quick Access Toolbar, before clicking the toolbar button, select the shape, picture, chart, table, SmartArt graphic, or other object, and add alt text.

How to make it really effective?

• Alternative text should be easy to read and understand so that people using reading software can continue with the rest of the message. Try not to be more than one or two sentences.
• Correct punctuation. Because screen readers use punctuation to know where to pause when reading content, it’s important to use proper punctuation in alt text.
• Do not use quotes. The ALT attribute added to the raw HTML uses quotation marks to identify where the campaign alt text begins and ends. If more quotes are entered, this could cause errors.
• Repeat the text that appears in the images. It is always better to keep important information in the main text of a message than in an image. However, if an image includes text, repeat that information in the alt text so that people using reading software don’t miss it.
• Do not repeat the same image caption. Image captions are read by screen readers and are displayed even when images are locked. That is why it is not convenient to repeat them in the alternative text. Alternative text should provide different information than the image caption.
• Take context into account. Context is the most important thing when it comes to writing alt text for an image. What is the relationship between the image and the content that surrounds it? Ask yourself what information people using reading software will be able to extract from the content around the image.
• Identify decorative images. If an image is purely decorative, briefly indicate this in the alt text so people using reading software can jump right into the rest of the message. For example, writing “Decorative image” is enough.
• Content test. When you’re done with your document, test that all the elements you’ve added alt text to display it correctly. You can use the text reading tool of the Adobe reader program for this.