In search engine optimisation (SEO), it is crucial to know link-related metrics in order to measure the authority and visibility of a website. There are many such measures to evaluate the authority of a website or a link.
Two of the most commonly used terms that are used by SEO professionals in tools such as Ahrefs are referring domains and backlinks.
Although they might sound similar at first glance, they are two different aspects of a website’s link profile. Knowing the difference between these two metrics can significantly impact how SEO experts plan and evaluate link-building strategies.
What Are Backlinks?
A backlink, no matter what it’s called, an “inbound link,” is a link that brings visitors from one site to another. When someone else puts a link on your site, that’s a backlink. To a search engine, backlinks serve as markers of trust and credibility. The more quality backlinks a site has, the better its chances of performing well in search results.
There may be different kinds of backlinks, like from body text, footer, or image links. Ahrefs monitors all the above types and shows the count of backlinks a target domain or URL receives.
But it can, and does, happen that a single domain can pass more than one backlink. Say you have a blog, and a news website links to your blog in five stories. You will have received five backlinks, all coming from the same domain.
What Are Referring Domains?
A referring domain is the individual website or domain name where backlinks originate. In the above example, even though five backlinks were created, they all originated from one referring domain—the news site. Therefore, in Ahrefs, this would be five backlinks from one referring domain.
Referring domains are typically viewed as a more significant measure for determining the diversity of a website’s link profile. Search engines value more the presence of backlinks from numerous different domains than the presence of many from one site. This is because the wider the spread of referring domains, the more likely it is that the content is valuable and trusted by many sources, not one.
Why the Distinction Matters
The difference between backlinks and referring domains is not only technical—it has strategic consequences. A site with thousands of backlinks but all from a few domains could be indicative of spammy or overuse of a few sources. Alternatively, a site with fewer backlinks but with a diverse range of authoritative referring domains could be considered more trustworthy and built organically.
Both of these metrics are displayed prominently in Ahrefs, but experienced SEO experts are more concerned with acquiring referring domains than with simply growing backlink counts. This is more in line with Google’s focus on link quality over quantity.
Assuming your site has 2,000 links and 300 referring domains, this indicates that, on average, each domain is pointing to your site between 6–7 times. While this is not in itself an issue, it could be something for closer examination. For instance, if a single domain accounts for 1,500 of the links, search engines would consider this manipulative or unnatural linking practices if the links are presented in poor quality situations.
Monitoring in Ahrefs
Both measurements can be monitored easily by Ahrefs. Within its Site Explorer feature, one can observe the referring domains and backlinks along with proper breakdowns, including the type of link (no-follow or follow), anchor, and linking pages’ authority. Over time observation, one is able to check for new opportunities to link as well as see whether there have been any spammy links to be disavowed.
Conclusion
Although both referring domains and backlinks are important SEO metrics, they provide distinct information. Backlinks show the quantity of links to a website, while referring domains show the variety of linking domains. For sustained SEO success in the long term, acquiring high-quality backlinks from a variety of quality domains should be the central theme of any link-building campaign. Software such as Ahrefs offers the data required to make effective decisions and build a robust, sustainable link profile.