All IMG elements are required to contain either the ALT or LONGDESC attribute.
Every image item requires to have an alt text description or long description. Add alt attribute and/or longdesc attribute to every image tag with a meaningful description of the image.
The alt text of an image cannot contain the word "image".
e.g. <img src="Images/BackToTop.GIF" alt="Click this image to return to the top of the page" width="59" height="13" />
In the above example, the description of the alt text is "Click this image to return to the top of the page". Change the description of alt text to "return to the top of the page" and it will pass the ADA checkpoint.
The length of the alt text of an image should be within 8 to 80 characters.
Based on the CSU ATI checkpoint requirements, the length of the alt text cannot be shorter than 8 characters and cannot be longer that 80 characters. If the alt text is greater than 80 characters, the long description attribute should be used.
Ensuring a contrast ratio of at least 4.5:1 exists between text (and images of text) and background behind the text
In order to make sure the user can read text that is presented over a background. text letter should maintain 4.5:1 contrast ratio with the background. The contrast ratio can sometimes be maintained by changing the relative luminance of the letters as the relative luminance of the background changes across the page. Another method is to provide a halo around the text that provides the necessary contrast ratio if the background image or color would not normally be sufficiently different in relative luminance.
Text indicating where to download plug-in/application in order to open the link(s) on the page.
When a web page requires an applet, plug-in, or other application be present on the client system to interpret page content, the page must provide a link to a plug-in or applet. The checkpoint is looking for the download description containing phrases like:
For PDF format links: download acrobat, download adobe, download pdf viewer, get adobe reader, adobe reader required, require pdf reader; Adobe Acrobat Reader can be downloaded at http://get.adobe.com/reader/
All anchor elements are required not to use the same link text to refer to different resources.
e.g. <a href="news.html">Click here</a> to the news page. <a href="events.html">Click here</a> to the events page.
In the above example, there is a "click here" anchor link text linking to the news page, and another "click here" anchor link text linking to the events page. This issue is caused by using the same link text on one page but linking to different URLs. The title attribute with the corresponding link description should be added to the anchor element.
Anchor example with title attribute added: <a href="news.html" title="news page">Click here</a> to the news page. <a href="events.html" title="events page">Click here</a> to the events page.