I maintain a couple of web sites for a couple of small companies. If you’re maintaining web sites, you inevitably have links to outside your site. Now, I’m aways careful to make sure all the links work on the site when I set it up. But what happens when things change outside your site? Who has time to check it out and make sure your links aren’t a road to nowhere?
Fortunately, there are tools to help with that. One I like using is called LinkChecker, which is free (but donations are accepted). LinkChecker runs on Macs, Windows, and Linux. It can be run as a GUI, as a command-line program, or even as a CGI web program. It checks not only for broken links, but also links that are now redirected, as well as trying to access mail servers for mail links and verify the email address in the link.
It’s certainly helped me out when it was brought to my attention that one of the links on a site I maintain was now dead. I used LinkChecker and found a few others – including a couple of internal site links I thought I had already fixed that I hadn’t quite (new links were there, and the old ones were as well, but they were nearly impossible to get to).
You can configure LinkChecker to only go a certain depth into the site (or all the way down), and to skip or check different types of links if you want (as an example, you might not want to follow “ftp” links, which are on by default). It runs multiple threads, so it moves along pretty quickly, even on sites with a lot of links.
If you maintain any web sites, LinkChecker it a pretty nice tool, and you can’t beat the price (of course, it’s always great if you can donate to the author if you feel the program is worthwhile to you).