One way to keep your site healthy from an SEO perspective is to only deliver quality content to Google. Anything non-relevant 'dillutes' the quality of your site. Often I see Joomla sites where this goes wrong. There are roughly 3 major reasons for this: Really crappy content, poor articles with only very little text and in itself relevant content that is useful for users, but that should not go in the Google index.
Now maybe you think, this is not relevant for your site, but chances are pretty high it probably is. Whatever the reason is that this content is there, make sure to review it and decide to either remove it or tell Google not to use it in its index. Let's discuss this in more detail, and also describe how to fix this:
I already mentioned there are a number of possible reasons for irrelevant content. In some more detail, these are the major 3 reasons:
Items 1 and 2 should really be avoided at all costs while item 3 is not too bad but needs to be addressed too.
Even though you may think your site is healthy enough, you would be surprised to find out that Google has indexed some pages that you even didn't know you had. A possible reason for this are the URLs Joomla creates for automatically, even without setting up menu-links for this. As an example, on every Joomla site there is a link to a login page at the following URL: /index.php?option=com_users&view=login. And there are more.
Finding out whether these URL's isn't too hard, there are multiple methods for this:
Now tell me there isn't a URL here and there that you didn't know about...
Now that you know what should go, it's time to do something about it. Anything that is really crap, like sample-content that you forgot about: simply remove it, and don't forget to check internal links to the removed content. If you simply remove it, Google will encounter 404-errors for this for some time. For stuff like this, this is perfectly fine. A 404 is a valid code, which simply means that the page is no longer there. Eventually, Google will ten update its index. If you think these items had some relevance though, you can always 301-redirect it to a valid page.
Then relevant stuff like the items listed under item 3 (sign-in, register, terms & conditions, etc.): of course do not remove it. However, these pages should not show up in the search results. People should see records for the great content you have, like this shiny laptop that you are selling in your webshop. If they're really interested, they will be able to click on your terms and conditions from within your site. The best option for these URL's is to set a Noindex attribute using the robots-metatag. This will simply tell Google not to put this URL in the index.
Usually, you can set the tag in the Joomla article or menu-item. This counts for actual articles you created. The exception are the funny non-SEF URL's for the sign-on page and stuff like that. A possible way to deal with those is to create a (hidden) menu to these options and then use the menu-item to Noindex them. And finally, make sure your sitemap only includes the relevant links.
You can also read this Moz.com blogpost. It is the article that inspired me to write this actual post, and it gives you some more advanced tips too.
Joomlaseo.com is fully built and written by Simon Kloostra, SEO Specialist and Webdesigner from the Netherlands. I have also published the Joomla 3 SEO & Performance SEO book. Next to that I also sometimes blog for companies like OStraining, TemplateMonster, SEMrush and others. On the monthly Joomla Community Magazine I have also published a few articles.