Optimizing your internal link structure

SEOs often focus heavily on accumulating inbound links, but don't overlook links within your site. Columnist Dave Davies shares his guide for how to structure your site's internal links.

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Internal link structures.

Let’s begin by quickly talking about what an internal link is. An internal link is a link from a webpage to another resource on the same domain. That resource may be another webpage (what we’ll be focusing on here) but can also include links to media files, downloads and more.

Here are two primary considerations we need to make when thinking about our website’s internal link structure:

  1. Users. Obviously, you should first consider when thinking about where to place links on a page and where they should lead. We want to get users from where they are to where they want to go (or where we want them to go) as quickly and easily as possible.
  2. Search engines. Another critical consideration is how a search engine will view the internal links on your site and how they will pass their weight.

I’m going to leave discussions around the first point above to others stronger in design and UX and focus here on what we need to think about from an SEO standpoint when we’re viewing our internal link structure.

I’m going to assume that we all understand that broken links bleed PageRank and are horrible for SEO and UX, so we’ll skip that point and move on to the more technical side of link structures. So, let’s start with …

Anchor text use for internal links

Anchor text refers to the specific verbiage used in a text-based link to another page. The anchor text used as the hyperlink helps the search engines to understand the relevance to the target.

For example, a link in this site’s top navigation to the informational page on SEO uses the anchor text, “What Is SEO?” While there are a variety of factors involved with ranking and Search Engine Land is itself a very strong site, the page being targeted with this anchor text ranks #1 on both Google and Bing for “what is seo.”

So you might be thinking, “All right … time to jam in as many links as possible to as many pages using the primary phrase of that page as the anchor.” Please don’t. While you want to use the terms that will indicate to the engines what the subject of the target page is, you don’t want to overdo it.

We’ll get into the number of links on a page below, but let’s imagine a scenario on an e-commerce site selling widgets. Now let’s imagine a giant left-hand menu listing all 32 colors the widgets are available in and in all four sizes for each, each of which leads to a product page. You’d get a menu that reads:

Widgets

  • 1/4″ almond widgets
  • 1/2″ almond widgets
  • 1″ almond widget
  • 2″ almond widgets
  • 1/4″ blue widgets
  • 1/2″ blue widgets
  • 1″ blue widgets
  • 2″ blue widgets
  • 1/4″ cyan widgets
  • And so on

You’ve definitely hit your anchor text, but it might read just a titch spammy — not to mention it would ruin the proper sculpting of your PageRank passing. The goal is to use your anchor text when appropriate. Use verbiage that includes your keywords when possible and will also be descriptive to your human visitors.

If you’re wondering how you might go about addressing the menu above, we’ll get further into that below when we discuss the sculpting of PageRank.

Minimize duplicate links

Sometimes having multiple links to the same page is inevitable. Most sites have at least two links to their home page in the header (the first being the logo and the second being some type of “Home” link).

While ensuring that your visitors can quickly get where they want to go, it’s important to keep your internal linking structure clean and reduce the number of links to the same page to only those required by your human visitors. Footers are often the first place to look for violations of this principle.

The reason this is important is that the way multiple links are valued is unreliable and variable. Technically, two links to the same page should pass double the PageRank to that page based on the initial PageRank formula; however, whether it still does is not reliably known.

If it does not, then multiple links to the same page may either be ignored, or worse, bleed PageRank. I find the latter unlikely, but unknowns are never good. Further, if the additional links are simply ignored, then you have cluttered your page and made your visitors make more decisions for no reason.

Further, multiple links also makes the anchor text passing unreliable. At times, only the anchor text of the first link is counted, but it’s believed that at other times, both may have weight. So essentially, adding multiple links for SEO from an anchor text perspective has as much chance of causing issues as of helping.

The only exception to this rule I can think of that’s more or less globally applicable is to the home page. The reason for this is that the first two links to the home page are generally the logo and a link with the anchor text “Home.” Neither of these is particularly SEO-friendly, other than their prominent placement on the page. So adding a third link somewhere that includes keywords may assist in helping the engines understand that the target is not about “home” but about “widgets.”

Pass weight from your linked-to pages

All pages on your website have PageRank. This weight is accumulated from within your site, but its origin is other websites. Sites linking to you pass PageRank, and the page they target on your site gets it. From there, the PageRank flows within your site based on your internal link structure. Basically, what this means is that links from your most linked-to pages tend to carry the most weight.

Of course, I’m not suggesting that you hunt down your linked-to pages and fill them with internal links. But it is worth looking into whether there is a logical way to link to some of your more relevant and important pages using anchor text to reinforce their subject.

Sometimes it might be related products, and other times, simply related posts or articles, but you might as well make good use of this PageRank rather than leaving it to the general global structure of your site to work with unique scenarios.

A further consideration is obviously to insert links to key pages in content you’re developing that is likely to acquire links. If you’re creating a solid white paper or quality blog post, for example, and you’re pretty sure it’ll attract links, then you’d be well served to work in some links to key relevant pages that could use the weight in advance.

PageRank sculpting

When I refer to PageRank sculpting, I’m not referring to the antiquated practice of using nofollow on links to unimportant pages to focus the PageRank flow to the more important ones. This doesn’t work and hasn’t worked in many years.

What I’m referring to is structuring a site so that PageRank flows through it in a logical way to pass the most weight to the pages that need it. For example, a page targeting “blue widgets” is likely going to need more weight than “1/4″ blue widgets.”

Let’s take a look at a simple example of PageRank flow through a site …

PageRank flow through simple site.

To keep the formula simple, I’m going to use a starting home page value of 100. I’m also going to ignore the percentage loss in PageRank as a link is followed.

For those unfamiliar with this concept, I’ll discuss it briefly below, but for now, let’s focus on how PageRank would flow through this site. We are going to also treat the math as if each page only links to those below it. Assuming that each page links to the pages below it and directly above it, including the Home page, we end up with the following:

The Home page passes:

  • 33.3 to the Almond Widgets page
  • 33.3 to the Blue Widgets page
  • 33.3 to the Cyan Widgets page

The Almond Widgets page passes:

  • 33.3 to the Home page

The Blue Widgets page passes:

  • 11.1 to the Home page
  • 11.1 to the 1/4″ page
  • 11.1 to the 1/2″ page

The Cyan Widgets page passes:

  • 16.7 to the Home page
  • 16.7 to the 1″ page

The 1/4″ page passes:

  • 5.6 to the Home page
  • 5.6 to the Blue Widgets page

The 1/2″ page passes:

  • 5.6 to the Home page
  • 5.6 to the Blue Widgets page

The 1″ page passes:

  • 8.4 to the Home page
  • 8.4 to the Cyan Widgets page

So, at the end, we end up with the following values:

  • Home — 180.7
  • Almond Widgets — 33.3
  • Blue Widgets — 44.5
  • Cyan Widgets — 41.7
  • 1/4″ — 11.1
  • 1/2″ — 11.1
  • 1″ — 16.7

So we can see that while the weight for the 1″ Cyan Widget page is higher in a structure with only one link in the Cyan Widgets grouping, the Blue Widgets page has more PageRank than the Cyan Widgets page, due to more being passed back up. This sets a scenario where the more items in a grouping (either products or simply categories of content on a publisher’s website), the more weight to that category.

Now, let’s look at a slightly more advanced scenario that is a better reflection of the way the web works, a scenario where each page links to the pages below it, those at the same level unless they cross categories, and back to the home page. For example, in this scenario, the Blue Widgets page would link to the Home page, the Almond Widgets page, the Cyan Widgets page, the 1/4″ page and the 1/2″ page. The 1/4″ page would link to the 1/2″ page, the Blue Widgets page and the Home page.

So let’s see how that weight passes:

Home page passes:

  • 25 to itself
  • 25 to the Almond Widgets page
  • 25 to the Blue Widgets page
  • 25 to the Cyan Widgets page

Almond Widgets page passes:

  • 6.25 to the Home page
  • 6.25 to itself
  • 6.25 to the Blue Widgets page
  • 6.25 to the Cyan Widgets page

The Blue Widgets page passes:

  • 4.17 to the Home page
  • 4.17 to the Almond Widgets page
  • 4.17 to itself
  • 4.17 to the Cyan Widgets page
  • 4.17 to the 1/4″ page
  • 4.17 to the 1/2″ page

The Cyan Widgets page passes:

  • 5 to the Home page
  • 5 to the Almond Widgets page
  • 5 to the Blue Widgets page
  • 5 to itself
  • 5 to the 1″ page

The 1/4″ page passes:

  • 1.04 to the Home page
  • 1.04 to the Blue Widgets page
  • 1.04 to itself
  • 1.04 to the 1/2″ page

The 1/2″ page passes”

  • 1.04 to the Home page
  • 1.04 to the Blue Widgets page
  • 1.04 to the 1/4″ page
  • 1.04 to itself

The 1″ page passes:

  • 1.67 to the Home page
  • 1.67 to the Cyan Widgets page
  • 1.67 to itself

Which gives us a final value of:

  • Home — 144.17
  • Almond Widgets — 40.42
  • Blue Widgets — 42.5
  • Cyan Widgets — 42.09
  • 1/4″ — 6.25
  • 1/2″ — 6.25
  • 1″ — 6.67

We can see here that the PageRank flowing spreads the weight across the key top category pages, reducing the weight passed to the individual sizes of colored widgets and the home page. In the majority of site structures, this is the desired scenario.

The question we might ask, however, is why we want a structure where the individual measurements in the more populated category (Blue Widgets, in this case) have a lower value. You might ask, wouldn’t it be better to spread out the categories to pass weight to more categories at the top level and fewer pages below? Let’s look at a basic example:

PageRank flow linear.

So, using the same structure as above (pages passing weight to others in the same size grouping, the one above it and the Home page:

Home page passes:

  • 20 to itself
  • 20 to the Almond Widgets page
  • 20 to the Blue Widgets 1 page
  • 20 to the Blue Widgets 2 page
  • 20 to the Cyan Widgets page

Almond Widgets page passes:

  • 4 to the Home page
  • 4 to itself
  • 4 to the Blue Widgets 1 page
  • 4 to the Blue Widgets 2 page
  • 4 to the Cyan Widgets page

The Blue Widgets 1 page passes:

  • 3.33 to the Home page
  • 3.33 to the Almond Widgets page
  • 3.33 to itself
  • 3.33 to the Blue Widgets 2 page
  • 3.33 to the Cyan Widgets page
  • 3.33 to the 1/4″ page

The Blue Widgets 2 page passes:

  • 3.33 to the Home page
  • 3.33 to the Almond Widgets page
  • 3.33 to Blue Widgets 1 page
  • 3.33 to itself
  • 3.33 to the Cyan Widgets page
  • 3.33 to the 1/2″ page

The Cyan Widgets page passes:

  • 3.33 to the Home page
  • 3.33 to the Almond Widgets page
  • 3.33 to Blue Widgets 1 page
  • 3.33 to Blue Widgets 2 page
  • 3.33 to the Cyan Widgets page
  • 3.33 to the 1″ page

The 1/4″ page passes:

  • 1.11 to the Home page
  • 1.11 to the Blue Widgets 1 page
  • 1.11 to itself

The 1/2″ page passes”

  • 1.11 to the Home page
  • 1.11 to the Blue Widgets 2 page
  • 1.11 to itself

The 1″ page passes:

  • 1.11 to the Home page
  • 1.11 to the Cyan Widgets page
  • 1.11 to itself

Which gives us a final value of:

  • Home  137.32
  • Almond Widgets — 33.99
  • Blue Widgets 1 — 35.1
  • Blue Widgets 2 — 35.1
  • Cyan Widgets — 35.1
  • 1/4″ — 4.44
  • 1/2″ — 4.44
  • 1″ — 4.44

So we see here that if we spread out our top level, we actually reduce the weight across the board.

These are obviously simplistic examples, but they do reflect the way weight passes overall. A top level that is too broad will reduce the weight of the entire site; however, a link structure that is too focused on driving a visitor down one linear path will also produce a scenario with too much weight at the top and bottom of the structure but not enough weight spread across the generally critical second tier (category pages, in our example).

The only structure we haven’t looked at is the flat structure (which I sadly see far too often). That is, a structure with a massive navigation that essentially links to everything. So let’s look at:

Flat PageRank flow.

In this structure we would see:

Home page passes:

  • 14.29 to itself
  • 14.29 to the Almond Widgets page
  • 14.29 to the Blue Widgets page
  • 14.29 to the Cyan Widgets page
  • 14.29 to the 1/4″ page
  • 14.29 to the 1/2″ page
  • 14.29 to the 1″ page

Almond Widgets page passes:

  • 2.04 to the Home page
  • 2.04 to the itself
  • 2.04 to the Blue Widgets page
  • 2.04 to the Cyan Widgets page
  • 2.04 to the 1/4″ page
  • 2.04 to the 1/2″ page
  • 2.04 to the 1″ page

Blue Widgets page passes:

  • 2.04 to the Home page
  • 2.04 to the Almond Widgets
  • 2.04 to itself
  • 2.04 to the Cyan Widgets page
  • 2.04 to the 1/4″ page
  • 2.04 to the 1/2″ page
  • 2.04 to the 1″ page

Cyan Widgets page passes:

  • 2.04 to the Home page
  • 2.04 to the Almond Widgets
  • 2.04 to the Blue Widgets page
  • 2.04 to the itself
  • 2.04 to the 1/4″ page
  • 2.04 to the 1/2″ page
  • 2.04 to the 1″ page

1/4″ page passes:

  • 2.04 to the Home page
  • 2.04 to the Almond Widgets
  • 2.04 to the Blue Widgets page
  • 2.04 to the Cyan Widgets page
  • 2.04 to the itself
  • 2.04 to the 1/2″ page
  • 2.04 to the 1″ page

1/2″ page passes:

  • 2.04 to the Home page
  • 2.04 to the Almond Widgets
  • 2.04 to the Blue Widgets page
  • 2.04 to the Cyan Widgets page
  • 2.04 to the 1/4″ page
  • 2.04 to the itself
  • 2.04 to the 1″ page

1″ page passes:

  • 2.04 to the Home page
  • 2.04 to the Almond Widgets
  • 2.04 to the Blue Widgets page
  • 2.04 to the Cyan Widgets page
  • 2.04 to the 1/4″ page
  • 2.04 to the 1/2″ page
  • 2.04 to the itself

Which gives us a final value of:

  • Home — 126.53
  • Almond Widgets — 26.53
  • Blue Widgets 1 — 26.53
  • Blue Widgets 2 — 26.53
  • Cyan Widgets — 26.53
  • 1/4″ — 26.53
  • 1/2″ — 26.53
  • 1″ — 26.53

So you have far more weight to the size pages for the colors, however, they have the same weight. For this to be the logical structure, you’d need to have the same competition and desire to rank for “1/4″ blue widgets” as for “blue widgets,” which is unlikely and, on a global scale, horrible both for users and for SEO.

The goal

The goal, then, is to organize the site into logical categories — understanding that categories with more content will be stronger and keep deeper levels outside of the main navigation — or you’ll be reducing the global strength of the most important pages (i.e., the pages that need the most weight to rank). You need to keep your navigation clean and use the anchor text most appropriate for the link target, provided that it reads properly to humans.

While a clean and well-optimized internal link structure is no magic bullet to get you to the top of the rankings, it is critical to getting the most out of your website, ranking for the widest array of terms, and even aiding your visitors in getting from point A to point B (hopefully, your “Thanks for buying your widgets from us” page) as quickly and easily as possible.


Opinions expressed in this article are those of the guest author and not necessarily Search Engine Land. Staff authors are listed here.


About the author

Dave Davies
Contributor
Dave Davies is the Lead SEO for the Machine Learning Operations company Weights & Biases. He got his start in SEO in the early 2000s and in 2004 co-founded Beanstalk Internet Marketing with his wife Mary, who still runs its day-to-day operations. He hosts a weekly podcast, speaks regularly at the industry's leading conferences, and is proud to be a regular contributor right here on Search Engine Land.

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