Are there broken links on your site? Have you removed some old pages while forgetting to clean up the links pointing to those pages? Did you change your file structure and leave some legacy links behind? You may not even know if you have these issues, but the search engines do.
Do these broken links affect your search engine rankings? Out of curiosity, I asked some colleagues in the industry this question and the general consensus was they don’t even worry about it as an organic factor, which leads me to think they do not believe this affects rankings. Well, I am fairly certain this is incorrect for a number of reasons. Broken links can degrade your rankings on a site wide basis. I recently wrote on the fact that search engines rank individual pages and not whole sites, but I also mentioned there are a few site wide ranking factors. I believe this is one of those factors.
Let’s set aside for a moment that having broken links on your site is bad for a wide variety of user experience reasons and focus on why it is bad specifically for search engine rankings.First and fore-most, the search engines tell you specifically not to publish pages with broken links. The Google Webmaster Guidelines, can be vague at times, but for important issues they are fairly blunt. In this particular case the warning against broken links is tucked right in between the importance of Title tags and issues concerning dynamic URLs, both high profile SEO issues.
– Make sure that your TITLE and ALT tags are descriptive and accurate.
– Check for broken links and correct HTML.
– If you decide to use dynamic pages (i.e., the URL contains a “?” character), be aware that not every search engine spider crawls dynamic pages as well as static pages. It helps to keep the parameters short and the number of them few.
Google in particular has been very vocal about wanting to provide quality pages to its users. Taking a queue from it’s AdWords product and the “Quality Score” assigned to advertising landing pages, it is not impossible that a number of organic factors are combined to produce a site “Quality Score” for organic as well. Broken links would be a sign of a poorly maintained web site and would surely affect this “Quality Score”.
Now from a search engine spider standpoint, when a broken link is found, that equates to a dead end. If the missing page returns a 404 error, the search engine will identify the page as non-existent and catalog the pages linking to it. If the page linking to the 404 error remains on this list for too long or has too many links to 404 errors, in all likelihood this would have a negative effect on the “Quality Score” of that page.
One or two of these issues is not going to drop you off the first page of the results; however, long term publishing of broken links can degrade the overall quality of your site both in your visitors eyes and the search engines.