If your site has lot of external links, it is a great idea to open external links in a new window that will reduce bounce rate of your site which is good from SEO point of view.
Again if your post contains of of affiliate links, adding a rel=”nofollow” tag to external links is good idea because that will ensure search engine will not follow those links and associate them with your site’s rankings.
WP External Links plugin will do both the activates with ease, it will open external links in a new window also add rel=”nofollow” tag to the external links.
After activating the plugin, you will find a new option in your WP Admin called “External Links”, You need to setup the options as per your requirement.
Now, you have the option to choose where you want to open the external links, select the second option which will ensure that your site open external links in a new window.
This is one of the most important part of the plugin, you have the option to ask the plugin to ignore some of the important sites where you are linking. Every time you write a new article and link to some credible source come back to this page and update the list, that means this list will keep on expanding.
In the SEO setting options you have the tick box to add nofollow and external, you can choose any of them or both as per your need.
This plugin also provides you option to set icon for outgoing links, that will indicate users if it is external link or not.
So, if you want to open external links in a new window, just download the plugin from the link below and follow the instructions written in this post.