Some people simply don’t like the look of underlined text; others feel it makes their website look too “busy”. Whatever the reason, this is a question I have been asked many times over the years.
I personally favor underlining links as much as possible because it is a standard recognized by everyone. However, there are ways to display links clearly without underlining them.
Jared Spool, a usability expert, has written an interesting article on the subject and concludes that, while it may not be absolutely necessary to underline links, these important issues must still be considered:
Never underline anything that is not a link
People are used to clicking on underlined text; if you underline something that is not a link, they can become confused and frustrated.
Don’t Mix: Use the same style everywhere
Use a single style for your links and do not use it for anything else. If your link style is Bold/Navy Blue/Arial, then everything that is written with that style should be a link.
Don’t use underlined links for certain information and not for others; visitors will have no way of knowing what is a link and what isn’t.
When there is underlined text on a page, people automatically direct their eyes to it.
Underlining links is a good way to grab users’ attention; don’t dismiss it too quickly. Studies have shown that people move their eyes from link to link within a web page.
For more information, read Jared’s article; he uses screen shots of several websites to illustrate his point.