By Bruce Clay

Part of Search Engine Optimization All-In-One For Dummies Cheat Sheet

Your hard work on search engine optimization (SEO) won’t matter if your server isn’t set up to properly deliver pages and codes to search engines and your customers. You have to keep your server happy and healthy. Use this table to diagnose server problems, sort out redirects, and ensure that everything is working as it should, and you’ll minimize SEO problems.

Code Description Definition What It Means
200 OK The web page appears as expected. You want to see this status. Your server and web page have the
welcome mat out for search engine spiders (and users, too).
301 Moved Permanently The web page has been redirected permanently to another
web-page URL.
When a search engine spider sees this status code, it moves
easily to the appropriate new page. A 301 Redirect status
doesn’t cause a problem for search engine optimization.
302 Found (Moved Temporarily) The web page has been moved temporarily to a different
URL.
This status should raise a red flag if you find it on your web
server. Even though people claim legitimate uses for a 302 Redirect
code, this code can cause serious problems for your optimization
efforts. Spammers frequently use 302 Redirects maliciously, so if
you don’t want a search engine mistaking your site for a spam
site, avoid them.
400 Bad Request The server couldn’t understand the request because of bad
syntax.
A typo in the URL could cause this status. Whatever the cause,
you don’t want to block a search engine spider from reaching
your content pages, so investigate what’s causing this status
code on your site.
401 Unauthorized The request requires user authentication. Usually, this status means that you need to log in before you
can view the page content. Not a good error for spiders to
hit.
403 Forbidden The server understood the request but refuses to fulfill
it.
If you find this status code on your website, find out why. If
you want to block the spiders from entering, have a good
reason.
404 Not Found The web page isn’t available. You see this error code as the Page Cannot Be Displayed page
that appears when a web site is down or nonexistent. You definitely
don’t want a spider following a link to your web site only to
be greeted by a 404 error! That’s like visiting a house and
finding the lights off and the doors locked. If your server check
shows that you have a 404 error for one of your landing pages, fix
it ASAP.
500 and up Miscellaneous server errors The 500–505 status codes indicate that something’s
wrong with your server. Check them out.