The alt
attribute is required in the img
tag. It is there to provide information to those who are unable to see the image. This may include the visually impaired (perhaps using a screen reader), those using a non-graphical browser, or those with images disabled. In cases where the image is purely for formatting, the alt
attribute should be set to an empty string (alt=""
).
The alt
attribute is not supposed to be rendered as a tooltip. As far as I know, Internet Explorer for Windows is the only browser that does this.
The title
attribute "offers advisory information about the element for which it is set". It is not required, and should only be used in situations where it provides additional useful information not already present in the element for which it is set. The title
attribute is commonly rendered as a tooltip in graphical user agents (browsers).
See The alt and title attributes for more information.
Your graphical menu could be designed in one of many ways, so it's hard to say what, if anything, could be changed. What you need to consider is:
The accessibility of your navigation menu to those who do not see the site in the same way as you do. Is it possible to navigate your site in a text only browser such as Lynx? What happens if you turn images off? What happens if you turn stylesheets off? Turning images off is probably quite rare now, and is a tricky one to handle - it's a judgement call.
Is it an alt
or title
attribute that is causing the tooltip to be rendered? If it's the former, then those fortunate enough to be using a proper browser won't see the tooltip.
Is it really a problem in the first place? Considering the possible accessibility issues that could result from removing it, does it really matter?
Search engines are designed to find content that is useful to people. If your site doesn't make sense when viewed in a text-only browser, it probably won't make sense to a search engine. Design your site for people, not search engines.