What are internal links, I hear you ask?
They’re links from one page on the same domain to another.
Every website has them. But what most people don’t realize is that—when used strategically—internal links can significantly boost a site’s performance in the search engines.
In this case study, Ninja Outreach explains how they used internal links to help boost organic traffic by 40%—a stat that’s backed up by our organic traffic estimates for ninjaoutreach.com:
In this post, you’ll learn why internal links are critical to SEO success and how to create a smart internal linking strategy for your website.
Why internal links are important for SEO
Google uses internal links to help discover new content.
Let’s say that you publish a new web page and forget to link to it from elsewhere on your site. If we assume that the page isn’t in your sitemap, and doesn’t have any backlinks, then Google won’t know it exists. That’s because their web crawler can’t find it.
Here’s what Google says:
Google must constantly search for new pages and add them to its list of known pages. Some pages are known because Google has already crawled them before. Other pages are discovered when Google follows a link from a known page to a new page.
Pages with no internal links pointing to them are known as orphan pages—more on those later.
Internal links also aid the flow of PageRank around your site. That’s a big deal. Generally speaking, the more internal links a page has, the higher it’s PageRank. However, it’s not all about quantity; the quality of the link also plays a vital role.
Here’s a simplified view of how PageRank works:
Google axed public PageRank scores in 2016. However, PageRank remains a core part of their ranking algorithm. We know this because they said so.
This is likely part of the reason Google states that:
The number of internal links pointing to a page is a signal to search engines about the relative importance of that page.
Google also looks at the anchor text of internal links to better understand context, as confirmed in this tweet by John Mueller:
In other words, say that you have a page about blue widgets. You have multiple internal links pointing to that page with anchors like widgets, blue widgets, and buy blue widgets. Those help Google to understand that the page:
- Is about blue widgets, and thus:
- May deserve to rank for blue widgets and other relevant terms.
Notice that I bolded the word “may” there?
Just because your page is about a particular topic doesn’t necessarily mean that it deserves to rank for related keywords.
Google also states that internal linking structure can affect sitelinks. Not a huge deal, but something to keep in mind nonetheless.
Now, at this stage, you might be thinking “so if I wanted to rank for blue widgets, I should probably just add as many internal links as possible to that page with blue widgets as the anchor text, right?”
Kind of, but that way of thinking can lead to low‐quality and unnatural internal links.
Case in point:
You need to think smarter, and it all begins with your initial site structure.
How to set up the ideal internal link structure
Think of your website as a pyramid with the most important content at the top and the least important content at the bottom.
Most websites have the same page at the top of the pyramid—their homepage. Under that, they have their next most important pages—about us, services, products, blog, etc. Under each of those, they have slightly less important pages—individual products and service pages, blog posts, etc.
But you shouldn’t link all pages on one level of the hierarchy to all pages on another.
You need to keep relevance in mind.
The art of siloing
Siloing is the grouping together of topically‐related web pages via internal links.
For example, imagine that we have a website about countries and cities with these pages:
You can tell that each page falls into one of two distinct groups:
- Pages about countries
- Pages about the cities in those countries
So this is likely how you would “silo” these pages:
Each country page acts as a “hub” and links to subpages about related cities (and vice‐versa). This creates a topic cluster—a group of interlinked pages all closely‐related to the same topic.
Three benefits of this are:
- Users will have an easier time navigating their way around your site
- Crawlers will have an easier time understanding your site structure
- More “authority” is transferred to your most important pages (because subpages link back to hub pages and vice‐versa)
But there’s another, often overlooked benefit—this kind of structure can help search engines to understand the context of your content better.
Let’s say that I have the following page: domain.com/squash
Is that page about butternut squash, or perhaps the sport, squash? Who knows?
Well, let me reveal that this page is part of the following silo:
Now, what do you think?
Another overlooked advantage of silo structure is that—because you’re linking to and from topically‐related pages—there usually are plenty of opportunities to do so using relevant anchor text.
For example, it makes total sense to link from a page about fruits and vegetables to one about butternut squash with “squash” as the anchor text.
You don’t have to shoehorn that link into an unrelated page as we saw earlier.
Looking to learn more? Read Bruce Clay’s infamous guide to SEO siloing.
How to audit your internal links for issues
Everything above makes sense. But unless you’re starting a site from scratch, things aren’t always as organized as you’d like.
That’s why you should audit your existing internal links before adding more to your site.
This isn’t as difficult as it sounds. The first step is to crawl your site in Ahrefs Site Audit tool.
Here’s how to do that:
There are ways to do some of the stuff mentioned below without crawling your site. I will mention these as we go along. However, if you’re an Ahrefs user, my recommendation is to set a crawl going to ensure that you have the freshest data to work with.
Once the crawl is complete, check for these five issues:
1. Broken internal links
Site Audit > Internal pages > 4XX page
This report shows you all broken internal pages on your site.
These are bad because they waste “link equity” and result in poor user experience.
I recommend sorting the “No. of inlinks” column from high to low to prioritize pages with lots of internal links pointing to them.
Here are a few ways to solve such issues:
- Reinstate the broken page at the same URL (if deleted by accident).
- Redirect the broken page to another relevant URL. Update or remove all internal links pointing to it.
If you’re opting for solution #2, you can see all the inlinks to the broken page by hitting the corresponding number in the “No. of inlinks” column.
It tells you the referring page and anchor text, which makes it easy to find and remove/update them.
Learn more in our full guide to finding and fixing broken links.
No time to crawl your site? Try this:
Site Explorer > enter your domain > Best by links > add a 404 filter > switch to “internal” links > sort by dofollow internal links
Note. You should also sort by nofollow internal links. All broken internal links should be fixed.
Just click on the number of internal links to see the actual links.
Using Site Explorer instead of Site Audit is useful for when you want to see broken internal links on a third‐party website without having to run a full crawl.
2. Internal links to redirected pages
Site Audit > Internal pages > 3xx redirect
This report shows you all redirected pages (3XX) on your site.
Sort by “No. of inlinks” (high to low) to prioritize the pages with the most internal links pointing to them.
It’s important to note that not all of these will be issues. For example, if you have internal links pointing to moved and redirected pages (e.g., http://domain.com/blog → https://domain.com/blog), then it’s likely nothing to worry about.
Still, there’s no harm in updating these redirects to remove the additional “link hop.”
Either way, be on the lookout for pages that redirect to something not‐so‐relevant.
Case in point:
That’s 20 internal links to a specific brand of shoes, which now redirects to a generic women’s footwear page. Even worse, if we click on the number of inlinks, we can see that the anchor text used for these links is “Jeffrey Campbell” (the name of the brand).
That’s misleading, and those links should be removed or updated.
You can also use Site Explorer to find redirected internal links.
Site Explorer > enter your domain > Best by links > add a 301 filter > switch to “internal” links > sort by dofollow internal links
Note. Once again, you should also check and fix nofollow internal links.
3. Lots of internal links to unimportant pages
Site Audit > Internal pages > 2xx
This report shows the working pages on your site.
Sort by “No. of inlinks” (high to low), then start by skimming this list. If you see unimportant pages with lots of internal links, remove them. It may even make sense to delete those pages.
Here’s the kind of thing that you can often find with this tactic:
This blog post is about what’s new in June. As it’s now January of the next year, chances are this page isn’t particularly useful or getting a lot of traffic, yet it still has 16 internal links.
I would be inclined to delete this page and remove the internal links.
You can also customize the columns and sort by the number of “dofollow” inlinks instead, which can be useful for filtering out things like login pages with lots of internal nofollowed links.
It may also make sense to look for non‐indexable pages with many internal links pointing to them—especially if they’re “dofollow.” You can do that using the Data Explorer in Site Audit with the following filters:
Unless these links are essential for navigation purposes, they serve only to waste “link equity.”
Furthermore, if pages are set to “noindex, follow,” Google will equate them to “noindex, nofollow” in the long‐term. The result is an effective break in the flow of “link juice” through these pages, so it’s best not to internally link to them with “dofollow” links.