University of Nebraska - Lincoln Communications and Information Technology

Correct "Link Rot" Before It Destroys Your Web Page

If you have links to Web resources outside of your site, you need to be concerned about "link rot." Link rot is the decay of the World Wide Web links as the sites they connect to change or disappear. According to a January 31, 2002 article* in the Scarlet, a study conducted by John Markwell, professor of biochemistry in the Institute of Agriculture and Natural Resources, and David Brooks, professor of chemistry education in Teachers College, found that "nearly one in six (16.5 percent) of the links that had been viable 13 months earlier had disappeared or were nonviable because the content had changed, sometimes drastically." John Markwell and David Brooks received a grant from the National Science Foundation and documented link rot over a year's time in their sites for three courses. The study started in November 2000.

You should check your links at least once a year, preferably every six months. Depending on your site's purpose, the beginning of the calendar year or before a new semester, would be a good time to check your links.

Does this mean a lot of extra work for you to track all your links? No. There are programs or services, commonly called validators, that can help you check if the link still exists. Doctor HTML and NetMechanic are two examples.

Doctor HTML <www.doctor-html.com/RxHTML/> is one of the oldest and I've used it for several years. Doctor HTML offers the most comprehensive analysis and still offers single-page analysis for free.

  1. At the site, click on the "Single Page" link.
  2. Then enter your Web page address, select the option(s) you want analyzed. The "Single-Page Analysis" page opens with all options selected.
  3. If you only want to use the Verify Hyperlinks option, first click on the Clear Test Selections button and then select the Verify Hyperlinks option (see sample screen below).
  4. Click the Go! button and Doctor HTML will check your links and report the results.
Sample Screen from Doctor HTML Web site
Figure 1. Sample screen from Doctor HTML showing the list of items that can be analyzed.

If the report shows any dead links, you can click on the link's address to try to connect to the page or you can select the option for "further testing" on the results page and see an explanation. Use the online Help option for more explanation on this and other test options.

More validators, offering different services, can be found on the World Wide Web Consortium (W3C) Web Accessibility Initiative (WAI) "Evaluation, Repair, and Transformation Tools for Web Content Accessibility" page or at Yahoo > Computers and Internet > Data Formats > HTML > Validation and Checkers. None of these validators will check the content of the pages you link to — you need to do that on your own.

* Scarlet January 31, 2002 article: "Link rot hampers Web site usefulness"

Return to Tips, Tricks, and Techniques index

Communications & Information Technology |  CIT Computing

Questions or Comments: contact CIT Computing Staff
CIT Computing does not provide personal support to parties outside of UNL.

Institute of Agriculture and Natural Resources  Institute of Agriculture and Natural Resources (IANR)
 University of Nebraska-Lincoln
 Last updated March 24, 2004