should I block wordpress archive pages from search engines?

Question

I use WordPress and /sample-post/ URLs for my posts and /yyyy/mm/ for the archives.

Google has indexed the site fully.

Since the archives currently display full posts I've thought that I shouldn't let Google index the archive pages because they contain the full posts and that will be duplicate content. Thus my robots.txt contains:

Disallow: /2009/
Disallow: /2010/
Disallow: /2011/
Disallow: /2012/
Disallow: /2013/
Disallow: /2014/
Disallow: /2015/

Do you think this is good practice or would it harm my rankings and/or reachability?

Answer 1

Indeed, you need to avoid duplicate content on your Wordpress site. Wordpress often generates duplicate content between categories, archives and tags.

In order to fix this issue you can block URLs of archives in robots.txt but the best option is to put <meta name="robots" content="noindex, follow"> on archives pages to avoid getting these URLs indexed by Google.

To do this, you can download Wordpress SEO plugin from Yoast. When plugin is installed, you have an option to put this meta wherever you want (on archives pages, on tags pages, on categories pages...). You can go then to the menu of plugin: SEO => Titles and metas.

In my opinion, best pratices for SEO are to put this meta on archives and tags pages and let Google crawl categories pages. I always have avoided duplicate content on Wordpress site like this.