Source: Microsoft

Alternative text, also known as alt text or Alt Text, appears when you move your pointer over a picture or object. Alt text helps people who use screen readers to understand the content of images in your document. For many readers, this is the only information they have about the images and objects in your document. Alt text should be included for any of the following objects in your document:

  • Pictures
  • Clip Art
  • Charts
  • Tables
  • Shapes (that don’t contain text and are not in groups)
  • SmartArt graphics
  • Groups (all objects in this list, with the exception of shapes, should also have alt text when in groups)
  • Embedded objects
  • Ink
  • Video and audio files

Read more about the Approriate Use of Alt Text on WebAim.

Adding Alt Text in Microsoft Word 2010 for PC

  1. Do one of the following:
    1. – For a shape, picture, chart, SmartArt graphic, or other object, right-click it, click Format object (or Format Picture), and then click the Alt Text pane.
      To add Alt Text to the entire SmartArt graphic or chart, click the border of the SmartArt graphic or chart, and not an individual shape or piece.
      The first figure below displays the Format Picture menu on a PC in Word 2010.
      The second below figure displays the Format Picture menu on a Mac in Word 2011.
      Format picture menu in Microsoft Word 2010 on a PCFormat picture menu in Microsoft Word 2011 on a Mac
    2. For a table, right-click the table, click Table Properties, and then click the Alt Text tab.
  2. In the Description box, enter an explanation of the shape, picture, chart, table, SmartArt graphic, or other object. This box should always be filled in.
    The first figure on below, displays the Alt Text pane on a PC in Word 2010.The second figure below, displays the Alt Text pane on a Mac in Word 2011.

    Alt Text in Microsoft Word 2010 on a PCAlt Text in Microsoft Word 2011 on a Mac

  3. You can leave the Title box empty. This box should only be filled in if you are entering a detailed or long explanation in the Description box.
    NOTE Unless you have a complex chart or table, you will usually want to enter text in just the Description box. When you have complex content to describe, then filling in the Title field is useful so reading the full description is not necessary unless desired.

Make the Alt Text command readily available

If you frequently add alternative text to shapes, pictures, charts, tables, SmartArt graphics, or other objects, you can add the Alt Text command to the Quick Access Toolbar to create a shortcut to it. Note: The instructions below are for Word 2010 for PC.

  1. In the upper-left corner above the Ribbon, click Customize Quick Access Toolbar.
  2. Click More Commands, and then under Choose commands from click Commands Not in the Ribbon.
  3. Click Alt Text and then click Add.

To use the Alt Text command on the Quick Access Toolbar, select the shape, picture, chart, table, SmartArt graphic, or other object, before you click the toolbar button, and then add your alternative