Links and Hypertext
Link Text and Appearance

Long links

What is the maximum allowable length of link text? This is a reasonable question to ask. There is no set answer though. The most accurate answer is that the link needs to be long enough to convey the purpose of the link and no longer. Such a vague answer is open to wildly different interpretations, but perhaps this is not such a bad thing. Content authors need to have the freedom to give meaning to their content in the ways that make sense to them. Still, as a general rule, links should be as concise as possible without sacrificing meaningfulness.

Some authors have made links out of entire sentences, entire paragraphs, or even multiple paragraphs. These long links are almost certainly unnecessary, and are not user-friendly for screen reader users. Remember that screen reader users cannot visually skim through lengthy links. They must listen to the entire text. Some screen reader users get frustrated with long link text and impatiently move on to the next link if they cannot understand the purpose of the link after the first few words. Authors have no control over user behavior such as this, but they do have control over some of the reasons that can lead to users to get frustrated. Short, concise links are less likely to frustrate screen reader users than long, imprecise links.

Short links

What is the minimum allowable length of link text? This is another reasonable question, also with no set answer. In most cases, links should be words or phrases. In some instances, though, it may make sense to link a single character, letter of the alphabet, or numeral. For example, an alphabetical index may use each individual letter of the alphabet as a link.

The danger in using single characters as links—or in using any sort of small link (such as a 10 pixel by 10 pixel graphic)—is that some users will have difficulty clicking on such a small area. Someone with cerebral palsy, for example, may be able to use the hands to manipulate a mouse, but may have difficulty with the precise movements and muscle control necessary to click on a small link. This person may have to click to or three times to hit the target, and may end up clicking on the wrong link in the process, which would require the user to hit the Back button in the browser and try again.

Users do have some control over link size. They can purchase a screen enlarger like ZoomText or MAGic, which would render the link targets larger. Users can also enlarge the fonts in their browser without using a screen enlarger. The Opera browser allows users to enlarge the entire web page. In this sense, small links are not the worst accessibility problem that users can face. At the same time, authors can limit the potential damage by increasing the size of small links, increasing the font size of single character links, or making the target area larger by including non-breaking spaces in within the link.

URL readability

The first challenge is that URLs are not always human-readable or screen-reader-friendly. Many URLs contain combinations of numbers, letters, ampersands, dashes, underscores, and other characters that make sense to scripts and databases but which make little or no sense to the average person. In many cases, it makes sense to use human-readable text instead of the URL. The human readable link Constructing Accessible Web Sites - external link is more user-friendly than the link to purchase the book by the same title on Amazon.com, which consists of a 108-character link full of numbers, slashes, and text that is not very human-readable. (http://www.amazon.com/exec/obidos/ASIN/
1590591488/qid=1116957951/sr=2-
1/ref=pd_bbs_b_2_1/103-5755258-8204633 - external link)

Does this mean that URLs should never be used as links? No. If the URL is relatively short, there is probably no problem with using the URL as the link text. The key is to be considerate of screen reader users who must listen to the longer, less intelligible URLs.

URL length

The second problem is that some URLs are quite long, and some browsers refuse to let long URLs wrap to the next line, so the links extend off to the right beyond the visible area of the browser. These long URLs are generally generated by database-based web sites or web applications that transfer a number of variables through the web address itself. The above link to the book on Amazon.com is a perfect example. In fact, the long link text was modified by adding two spaces in the middle of the URL, to allow it to wrap to the next line. Mozilla-based browsers such as Firefox and Netscape do not allow long URLs to wrap unless the author introduces a space somewhere.

The original width of the screen shot below was over 2000 pixels, stretching across two monitors. Imagine placing a long link such as this in a web page. Users would have to scroll a long distance horizontally in order to read the entire thing.

Even worse, imagine listening to the link with a screen reader! Hardly anyone would ever have the patience to listen to all of that undecipherable mess. The link above could be shortened to "California seagull stock photos," since the link goes to a page with stock photography of California seagulls.