UX Movement posted Why External Links Should Open in New Tabs. I've never quibbled with any of Anthony Tseng's advice before, but this time I think he misses the mark somewhat.
True, for the primarily audience of this blog, I think opening external links in a new tab makes sense. I just went back to my posts this year and changed all external links. That's the key though, this decision has to be made based on the audience of the site.
Ever watch an older user or even young but not to savy user get dumped into a new browser tab? This sentence from UX Movement completely applies:
When a new window opens, it covers the user’s earlier window. The user is left confused and wondering how to get back.
Just replace window with tab and it still applies. All these users know is the back button.
So if your trying to appeal to browser savy users, go ahead and open external links in a new tab. If however you're trying to appeal to a broader audience with less browser know how, open external links in the current window or tab.