When changing permalinks in WordPress from an old format to a new, you risk loosing Google page rank.
On my blog I’ve had my permalink set to /archives/year/month/day/name-of-article. Looking at my web server log, very few used the archives sidebar, so I removed it. To make the link shorter I needed to remove everything except the article name. But when changing the permalink all the incoming links will get a 404 error from all old links, and the search result from Google, lowering your Google ranking. Not good.
So what we need to do is to redirect all the old links to the new shorter one. But we need to do it with a code 301 which tells search engines that the new link is permanent, thus keeping the page rank.
You could solve it by adding commands in the .htaccess file, but this is really a pain in the **s! So I tried to find a plugin that would do this automatically. Unfortunately There are a lot of plugins, some giving the code 302, which means that the redirect is temporary which is something we don’t want. Others didn’t work at all or had stopped being updated by the author. But I finally found a plugin that worked.
The name of the WordPress plugin is Permanent Redirect. It’s easy to install and after installing, all you have to do is to enter the old permalink and change the setting to the new one you want.
After looking at the Apache log, I could see that all the pages with the old URL got a 301 error code and then loaded the new one. Success! Trying to keep the number of plugins to a minimum in WordPress is a great way of speeding up your site, but I did not notice any speed degradation after installing.
Hopefully this will help you to find a plugin that really works, and that is easy to install.