A 2014 study released by the Harvard Law Review shows that an alarming number of hyperlinks go bad in a surprisingly short time.
Link Rot has been a problem from the very beginning of the web. Over time, websites can come-and-go and redesigns can change the location of content - the result being a link that is no longer available. In 2012, The Chesapeake Digital Preservation Group, a collaboration between the Georgetown Law and Harvard Law School Libraries, and the State Law Libraries of Maryland and Virginia, completed its 5th annual Link Rot study and found that 38% of hyperlinks are no longer valid after 5 years.
The Harvard Law Review study takes the concept one step further, introducing the idea of Reference Rot, whereby the web page is still valid, but the content has changed. The study shows that 70% of links within the Harvard Law Review and two other journal websites suffered from Reference Rot.
Of the two, Link Rot is the easier to detect. A valid webpage returns a code of 200 when accessed. Conversely, an invalid or missing webpage returns a code of 404. This makes it easy to create a script that crawls through a website checking each link for the appropriate code. Reference Rot is more problematic to detect as it requires an evaluation of the content to determine its continued validity.
We recommend to our clients - everyone, really - to check for Link Rot and make the appropriate corrections to content. The corrections will vary depending on the depth of the site and number of broken links.
If you drop us a quick note using the contact form on this page, we will email you some suggestions and outline some of the corrective measures you can take.