Internal Link Optimisation

Links are one of the most important ranking factors in Google’s algorithms. While there is much talk about external links (incoming links from other domains to yours) and a lot of effort, time and money is spent on obtaining them, internal links on a website attract relatively little attention – for no good reason! Internal links are a very powerful SEO tool and should not only be reduced to the navigation and the use of keywords in the link text. Behind many great SEO success stories lie clever internal linking strategies.

The differences between external and internal links.

Some fundamental thoughts on the importance of internal links:

According to their own statements, Google has indexed hundreds of trillions of pages on the internet with the help of their diligent bots. The Googlebot crawler requests individual pages and then follows the links on these pages. This way, it moves from page to page and saves the information found there on Google’s servers. A large part, if not even the lion’s share, of these trillions of pages are only accessible through internal and not external links.

Most subpages do not have any external links which Google could analyse as ranking factors

Let us simply take a yellow pages directory for all of Germany as an example and look at the usual indicators. With 12,000 cities and municipalities and 3,500 industry categories in the database we can already create 42 million (12,000 x 3,500) localised category pages. All of which have the opportunity to rank for at least 42 million different search terms (industry + city name). Whether it actually makes sense to deliver all of those combinations is another question, but even if we were to forgo half of the combinations, we would still be left with 21 million category pages. And we have not even started talking about the detail pages for the approx. 4 million companies or how we can include different neighbourhoods for the localisation.

Even if we had an army of link builders, it is not even remotely possible to provide each of these millions of pages with just one external (trustworthy) link with reasonable effort. Other websites with similarly large databases, like online shops or newspapers, will likely fare the same.

This is the reason why most subpages will not have any signals in the form of external links, which Google could take into account for the rankings. Even small websites will often only have external links to a certain proportion of the pages.

Pages can also achieve good rankings without external links

In reality, we see that a lot of pages manage to gain very strong rankings even without having external links. This is obviously a lot easier to do for long-tail keywords than for contested ones, but most keywords are part of the long-tail and, in total, many pennies saved are quite a lot of pennies earned. There are many examples where strong websites reached the top 10 rankings only thanks to their internal linking strategy (and good content).

External links increase Google’s trust in the domain

Now that we talked about “strong websites” we have nicely transitioned over to our next subject, external links. External links increase Google’s trust in the domain and the larger the trust is, the more Google will also trust your internal links. Due to this, both types of links are important and only through their interaction are we able to achieve complete success. External links are also necessary in order to get a large amount of pages into Google’s index. Having said that, it is simply too short-sighted to focus on external links only and treat your internal links like orphans.

Internal links also pass on link juice

Regardless of whether you like to call it PageRank, link juice, or link love. Internal links will pass it along, just like external links. One thing you cannot increase with internal links, though, is the domain pop. As soon as you have internalised this fact, you will also understand that, when it comes to the rankings, it makes a big difference if a page has 1–2 internal links or, for example, 100. A lot helps a lot. Of course, the more link juice the website receives via external links, the more link juice the internal links can pass on. This train of thought also demonstrates the interaction between the two types of links.

Internal links have many advantages

The great thing about internal links is that you are absolutely free to do with them whatever you like. You can freely decide on the number, placement and design of the link texts. This does not only sound fantastic, it is fantastic. All the links you have ever wanted can be created as internal links, at least on your own domain.

You also do not have to worry about any Google filters. While the extensive use of hard money keywords in the anchor texts of your external links will quickly lead to ranking losses, ever since the Penguin Update, we are not aware of any case where Google punished the use of money keywords in internal links – given that the content matches the keyword used.

In its own “Search Engine Optimization Starter Guide” Google recommends, “[…] the better your anchor text is, the easier it is for users to navigate and for Google to understand what the page you’re linking to is about.” (Under “Use links wisely”)

So, if the subject of the target page is “adidas running shoes”, for example, it is absolutely reasonable to internally link that page with the link text “adidas running shoes”, as often as you like. You are not in violation of any of Google’s guidelines by doing so. Sadly, most websites do not fully exhaust this possibility.

Wikipedia leads the way

The top 100 in the SISTRIX Visibility Index is presided over by by a wide margin. Every internet user can also certainly confirm from their own experience that it feels like Wikipedia is among the top 3 results for every second search query. So what is Wikipedia doing right?

Apart from being free of advertisements and having (relatively) good content, Wikipedia also links internally with hard money keywords like you wouldn’t believe. If the word “marketing” appears in a Wikipedia article, the word is linked to the Wikipedia article on marketing. If the word “credit card” shows up, the credit card article is linked to, and so forth.

Wikipedia probably did not originally choose this type of link strategy to improve its search engine rankings. It is much more likely that the folks at Wikipedia believed that this kind of internal linking is easy to understand for visitors and makes for good usability. Either way, the links work great, as far as Google is concerned. “Taking the user into account” brings us to the next topic.

What is the optimal link and what kind of links do I want to have?

You could write entire books about the optimal link, or you can put it in one sentence:

“The more real users actually click on the link, the better it is.”

These tend to be links that …

  • are in the content section of the website and not in the sidebar or the footer.
  • are towards the beginning of the text.
  • are recognisable as links (highlighted in colour, underlined).
  • have a clear and understandable anchor text that gives users at least a basic idea of what the linked page might be about.
  • are directly related to the text being read.
  • are on a page that gets as many visitors as possible.
  • have to compete with as few other links on the page as possible.

These and additional points can also be found in the Google Patent “Ranking documents based on user behavior and/or feature data”. In the patent specification, Google describes their idea that links, which are clicked on more often, should be more valuable and therefore pass on more link juice.

Google Patent Ranking documents based on user behaviour and/or feature data

You can find a good summary of the patent on SEO by the Sea.

While it is often very difficult to get such links from external websites, you can fashion your internal links exactly after the above criteria, and you should really make abundant use of this. Not only do these links improve your rankings with Google, they actually make your website more attractive for users. Both SEO- and user-orientation work hand in hand here.

This concept works for almost all websites and there are a lot of good examples online

Everyone who believes that this concept may work for Wikipedia but not for their own website should take a look at other websites with a high Visibility Index score. There are a large number of additional examples, from a wide variety of industries, within the top 100 SISTRIX Visibility Index list, where the intensive use of internal links shows to be a boon for both the search engine optimisation and the website usability.

To name just seven examples:

  • the links to manufacturers, authors, actors, categories, similar products, and more on Amazon’s product pages
  • the links to synonyms on the dictionary detail pages of
  • the links from keywords to the specific subject pages on
  • the large flyout navigation with many links to the individual sub categories on every page on
  • the keywords linking to related pages in the articles on
  • the linked ingredients on the recipe pages on
  • the linked business + city names on the category and detail pages on

If you take a closer look at some of these examples, you will notice that these internal links are one of the reasons why we consider many of these websites to be very convenient and user-friendly. In addition, you can certainly think of ways in which such a systematic internal link strategy, that is also helpful for users, can be sensibly implemented for your own website.

Add a second navigation within your content

When you check out the above examples and recall the sentence “The more real users actually click on the link, the better it is.“, it should become quite clear how you can optimise your internal links.

It is not user-friendly to just offer a standard navigation next to or above the content. The user’s gaze will have to leave the content and orientate itself anew on the website. This will inevitably be the cause for a loss of a large part of visitors.

Create a second navigation within your content through the use of internal links, so that users do not have to direct their focus away from the content. Offer links within the text that are the next logical click of the user. This could be additional detailed information, explanations, filters, similar content or overviews.

Both your users and rankings will thank you for it!

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