According to Wikipedia.org, a 404 Not Found Error Message is

an HTTP standard response code indicating that the client was able to communicate with the server but either the server could not find what was requested, or it was configured not to fulfill the request and did not reveal the reason why. 404 errors should not be confused with “server not found” or similar errors, in which a connection to the destination server could not be made at all.

For a not-so-technical person, that doesn’t help much, so here’s another way of saying it.  When a request is sent to your web server for a specific page, regardless of whether the request comes from a human user’s web browser, or a search engine spider crawling the web, the server returns 1 of many possible “codes”.  When the page requested cannot be found, that’s when a 404 code is returned.  It’s similar to getting that recorded message when you call a number that’s not in service anymore.  Instead of a voice saying “The number you are trying to reach is no longer in service”, however, you get a screen that says “404 Page Not Found”.

There are many cool 404 error pages out there.  Certain people in the world decided that since 404 errors are inevitable, then they might as well get a laugh out of them.  We’ve looked around the web and complied a list of great custom 404 pages, so check them out.  Maybe you’ll get some inspiration for your site.  SEO Best practice dictates, however, that 404 errors be avoided whenever possible and 301 redirects be used.  A 301 is a different server code that tells the requester that while the page they are seeking isn’t in service at this time, they can go to a new place instead to get what they were looking for.

That’s when Errorlytics steps in.  Errorlytics can log all the 404 errors that occur on your site.  After you set up a rule to generate a 301 redirect to a page that you specify, Errorlytics will eliminate that 404 error from ever occuring again.  Any inquiry for that URL will direct the user to the working page that you specify.

This awesome new widget is a great compliment to Errorlytics.  If you’re thinking about using the Google 404 widget, it may certainly help the visitor on that particular 404 instance.  However, if Errrorlytics is installed on your website, it will capture the info on this 404 for you and you can quickly create a rule that will ensure that the error will never occur again.  Creating positive visits from the start (pro-activity) rather than only trying to fix an already failed visit (re-activity) is the name of the game.

Google’s 404 widget is great from a user experience point of view.  It automatically performs searches that had to previously be done manually by the visitor.  What it doesn’t do, and where Errorlytics augments it, is the fact that if a user sees the widgit, a 404 error has already occured.  Errorlytics helps you avoid 404s to critical pages going forward – preserving your traffic and your SEO.