Published by Rob Lambert,
Almost all websites suffer from something called Link Rot where hyperlinks are left to decay resulting in many links that no longer go anywhere or point to out of date and unsupported pages.
The page they linked to may have been removed or they are simply no longer referencing the correct location.
It would make sense to keep on top of the links in the first place, thus avoiding time spent maintaining them, but this is easier said than done when faced with developing commercial sites and applications with many hundreds of links.
How to check for dead links
There are many tools out there that will scan your site, provide you with a list of dead-links and then suggest ways to fix the problem.
Download a link-checking tool, like Xenu, add in your URL and then go through the report.
How about running a dead-link checking tool as part of your Continuous Integration or Overnight Build Process? That way you can see dead-links after an automated test run.
Xenu Link Checker - http://home.snafu.de/tilman/xenulink.html
W3C Checker - http://validator.w3.org/checklink
If you’re interested in a career in Software Testing then check out my book Remaining Relevant And Employable (Tester’s Edition) - it’s packed full of ideas about writing good CVs, communicating your value to employers and doing well in an interview.