Inbound links, or backlinks as they’re commonly referred to, have mattered to SEO for as long as Google has been using an algorithm to rank search results.
Historically, having a greater number of inbound links has increased a website’s chances of earning high rankings in search results.
Links continue to be important to Google, but there’s more nuance to it compared to the days of PageRank.
Let’s look at the claims surrounding inbound links as a ranking factor, followed by evidence that either supports or debunks those claims.
The Claim: Inbound Links Are A Ranking Factor
Inbound links refer to links pointing from another domain to your website.
There are a number of claims surrounding inbound links as a ranking factor.
The first is simply that inbound links are ranking signals for Google’s search algorithms.
In other words, Google assesses the links pointing to a webpage when determining how to rank it in search results.
Other claims about inbound links relate to the strength of the ranking signals generated by the links.
Quantity is said to be one of those factors, with more links creating stronger signals.
The referring domain is said to be another factor, with high authority and relevant sources creating stronger ranking signals.
The next section dissects these claims and goes over what matters to Google when it comes to inbound links.
The Evidence For Inbound Links As A Ranking Factor
Google’s algorithm is founded on links.
PageRank, the algorithm on which Google’s search engine is built, depended solely on links to rank content when it was first introduced.
Describing to the public how its algorithm works, Google once stated:
“PageRank works by counting the number and quality of links to a page to determine a rough estimate of how important the website is. The underlying assumption is that more important websites are likely to receive more links from other websites.”
Google’s algorithm has since been updated to consider other factors, but inbound links remain an important signal.
The company says as much on its How Search Works microsite, which describes how Google’s algorithms assess webpage quality:
“We look for sites that many users seem to value for similar queries. For example, if other prominent websites link to the page (what is known as PageRank), that has proven to be a good sign that the information is well trusted.
Aggregated feedback from our Search quality evaluation process is used to further refine how our systems discern the quality of information.”
There’s no doubt that inbound links are a Google ranking factor. Now let’s look at the next claims.
Does the quantity of inbound links matter to Google?
The claim that the quantity of inbound links is a ranking factor has been refuted by Google.
Google’s John Mueller states that the total number of inbound links pointing to a website is “completely irrelevant” to search rankings.
Mueller explains why link quantity is not a factor, saying it’s a signal that can be easily manipulated.
He advises site owners not to focus on how many backlinks they have. Google may even choose to ignore most of a site’s inbound links and only look at the ones that are relevant. Mueller said:
“We try to understand what is relevant for a website, how much should we weigh these individual links, and the total number of links doesn’t matter at all. Because you could go off and create millions of links across millions of websites if you wanted to, and we could just ignore them all.
Or there could be one really good link from one website out there that is, for us, a really important sign that we should treat this website as something that is relevant because it has that one link. I don’t know, maybe from like a big news site’s home page, for example. So the total number essentially is completely irrelevant.”
In that statement, Mueller confirms that the authority and relevance of referring domains are taken into consideration, as well.
Inbound Links As A Ranking Factor: Our Verdict
To recap, here are the verdicts on all claims based on the evidence we’ve presented:
- Yes – Inbound links are a ranking factor.
- No – Quantity of inbound links is not a ranking factor. To be clear, this means just increasing your raw number of backlinks won’t help you, especially if the links are low-quality. However, there is one way that quantity can matter: having a large number of great links is always better than having a small number of great links.
- Yes – Relevance and quality of the referring domain is a ranking factor.