Adding Alternative Text to Images

In order to guarantee accessibility for all users, alternative, or ALT, text is essential for all images used in content delivered online. Screen readers, such as JAWS and NonVisual Desktop Access, cannot interpret images beyond location and file name, so we must manually provide descriptive text to images which screen readers can read to visually-impaired users. Depending on the software used, an important image file without ALT text may be ignored by the screen reader, or only its file name could be read.

Adding ALT Text to Images Embedded in Blackboard

When adding an image directly within a textbox editor in Blackboard, such as when creating an announcement or item, enter the ALT text on the Insert Image pop-up page.

1. Click the Attach Image button on the textbox editor toolbar.

Attach Image button on Toolbar

2. When the Insert Image pop-up page appears, browse for and attach the desired image.

3. Scroll down to section two, Image Options. Enter a brief description of the image in the ALT Text field.

Alt Text added on Insert Image page

4. When all options have been set, click the Submit button to add the image within the textbox.

5. To confirm ALT text is properly assigned, simply place your mouse over the image within the textbox. Your ALT text should be displayed.

Mouse over image displaying ALT text

Adding ALT Text to Images in Powerpoint 2007

1. Right-click on an image within a Powerpoint slide, then choose Size and Position on the drop-menu.

Options menu displayed when image is right-clicked in Powerpoint

2. Click the Alt Text tab on the Size and Position pop-up menu. Powerpoint assigns the filename as default alternative text for each image, which provides little information to screen reader users. Provide your own descriptive ALT text in its place. Click the Close button to save ALT text changes.

Alt Text tab on the Size and Position menu

Adding ALT Text in Word 2007

1. Right-click on an image within a Microsoft Word document, then choose Size on the drop-menu.

2. Click the Alt Text tab on the Size pop-up menu.

Options menu displayed when image is right-click in Word

3. The file name will be assigned as default alternative text. Provide your own description in its place. Click the Close button to save changes.

Adding ALT Text to HTML

The standard HTML tag for an image is:

<img src="filename.jpg">

Using an image file named "Quarrymen.jpg" as an example, a screen reader program will read the standard HTML image tag as, "Image, quarrymen dot j, p, g." File names typically contain little to no description of the image presented, and fail to provide important content information to visually-impaired users. To get a screen reader to read a description of the image, rather than the file name, we must assign the ALT text attribute, as seen below:

<img src="Quarrymen.jpg" alt="Teenage John Lennon performing with high school band, The Quarrymen">

Using this example, screen reader software will read the image as, "Image, teenage john lennon performing with high school band, the quarrymen."

Null ALT Text

Images that require no description, such as those used in borders and as content spacers, should be assigned null ALT text, which will prompt screen readers to ignore them. The proper null ALT text attribute is alt="", with no characters or spaces between the quotation marks. See the example below:

<img src="border.jpg" alt="">

Using the code above, screen readers will ignore the presence of the border image, and continue on to read more essential data.