Best Free Web Site Link Checker

Virtually all websites have dead or broken links in the same way that all software has bugs. Mistakes happen, content changes, file names and locations change, and external links change. And until you've checked links for some period of time, and learned what breaks them, you're likely to repeat the classic mistakes on a regular basis. ;-)

Link checkers work much like a search engine spider. They "crawl" your website looking for internal and external links that are broken. Crawling is recursive, meaning that the spider builds a tree of links leading from page to page until all branches have been explored. Spidering continues until it reaches a defined termination point. For example, when all internal branches have been examined, or when all first level external links have also been examined. A good link checker also produces broken-link reports that enable you to determine where the broken link is located, and why the link is broken.

Xenu's Link Sleuth is the only free link checker that I know of that does the whole job. I've used it for many years. It's simple, small, fast and accurate. It takes a while to learn how to use Xenu's Link Sleuth, and it can be daunting to understand the reports, but if you stick with it you'll come to appreciate the excellent job it does.

REL Link Checker Lite can do the basic task, but is limited to 1000 links, so you need to work in one sub-directory (if you have them) at a time for larger sites. It's hard to learn how to use RLCL, but it's easy to use once you figure it out. :-) HINT: Use REL's "Help". It is concise and useful. You'll probably be baffled without it.

The Link Evaluator extension for Firefox works well, but it only checks one page at a time. However it's useful when you want to do a quick check.

Web-based Alternatives:
Link Valet by Web Design Group spiders your website, like a search engine would, and provides a very nice broken link report. Broken links are listed by page location so it's easy to find and fix them. There is a recursion (depth of spidering) limit, but the report includes a list of pages that were not checked, so you can extend link checking deeper if you want.

Google Webmaster Tools reports the errors that the Google spider finds when it crawls your website. You'll find the link errors (not found) under "Web crawl errors" in the "Overview" section of the "Dashboard". The beauty of the link error report is that the details page shows the page(s) that contain the broken link(s).

The FreeFind search engine crawls your website to power their free site search. When finished FreeFind provides a very complete spider report, which shows all the broken links. The page that contains a broken link is not listed though, so it often takes some sleuthing to figure out where broken links are located.