Is there any evidence that linking to external quality, reputable and popular websites helps with ranking (directly or indirectly)? Is there an established correlation? Some posts on the web do claim it, but without providing any evidence.

It is known that if your website links to bad neighborhood, this will harm your reputation and authority, but does the reverse actually help? And, does it matter if the website is young or old in this case?


I have found this Moz video revealing there is a 0.04 correlation with ranking.

  • 1
    Good sites normally link out to good sites, I know that your looking for evidence but I'll try and dig some out... I'm currently testing this theory on a large scale. On 10 articles, 5 of which are linking out to other credible sites, while 5 do not. Aug 25, 2013 at 12:36
  • I believe this is the case, because if you search for anything such as How too, tutorials or anything such as that, these results normally have multiple refferences, take wikipedia as a example, they cite references (I know they already have massive amount of authority) but so does Amazon, Gumtree, Yell and they don't always appear in the top results unless the are lots of outbound on the page. Aug 25, 2013 at 12:38
  • I am interested in your findings. It will be interesting to compare them to Stephen's. Aug 25, 2013 at 13:17
  • No problem, just waiting on the pages to mature. Aug 25, 2013 at 13:50

2 Answers 2


Yes, there is evidence. Matt Cutts has indicated that linking to quality pages can be a positive ranking factor.


  • The statement is "parts of our system encourage links to good sites", but this post dates from June 2009. Curious to see what @bybe's results will be. Aug 25, 2013 at 16:34
  • @JVerstry when Google launched and the years following their site indicated the number of signals used to rank a page. From 50 or 100 then 200 then they finally just said hundreds of signals. As John Conde linked to a very credible source I would say this is the best answer, and it's doubtful they stopped factoring in a page linking to a more trusted source then itself. In people talk, it means you're not trying to be the best and you recognize a page being better than yours or with more valuable information or info that your visitors should find very useful. It's about trust and reputation.
    – Anagio
    Oct 14, 2013 at 20:57
  • @John Cone absolutely. Social networking is very important to Google. I often reference Wikipedia in articles and content I place on my websites or blogs. However, I make sure the outbound link is a nofollow. But as you state is only one of many signals Google takes into consideration when it comes to their algorithm. I would also describe this as linking out to authority sites. Referencing authority sites in your content is a smart thing too. Oct 31, 2013 at 11:56

I have never seen any direct evidence to support a direct ranking boost from quality outbound linking.

A few years ago I did an experiment. All the outbound links on the site were through an internal tracking redirect that was listed in robots.txt. Googlebot had no way of knowing that the links were external. We changed half the pages on the site to use a different tracking redirect that was not blocked by robots.txt. After a couple months, we saw no ranking difference between the pages that linked in a way that Googlebot could see vs the others. We also saw no ranking changes for the site as a whole. We did measure the position in the SERPs of the pages that we were linking to. For the pages that we linked to where Google could now see our link, rankings did rise modestly.

Personally, I think that Google has made a big mistake by not giving sites with quality outbound links a modest and distinct ranking advantage. Google relies on links to measure the quality of pages on the internet. Google should be providing an incentive to webmasters to recommend external resources. Having not done so, their algorithm is no longer as relevant or effective as it could be.

On the other hand, there are almost certainly indirect ranking boosts from linking externally when it pleases the user. When users click on external links on your site, doing so may prevent them from using the back button to return to the SERPs. Google measures the "bounce back" rate of users returning from your site to the SERPs and uses that as a strong signal that influences your rankings (particularly on a page by page and query by query basis). The experiment that we performed would not have measured any ranking changes from this because links were available to users in both cases.

  • Thanks for this great feedback. I believe that if Google gave boost to sites having quality links, it would be an open door to manipulation. Sites would create massive useless outbound links for the sole purpose of increasing their ranking. They would not necessarily be good sites though. And this would hurt Google's business. Aug 25, 2013 at 13:13

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