Referring domains vs backlinks: understanding the difference between these two counts is fundamental to assessing a domain's authority. A referring domain is a single website that links to you, regardless of how many links that one site sends. Backlinks is the raw count of all links pointing to your site. A single website can send 50 backlinks but counts as only one referring domain. The count of unique referring domains is a far more reliable signal of genuine authority than the total backlink count, because it is harder to game and better reflects how many independent sites vouch for your content.
Definition: the number of distinct sites linking to you
A referring domain is a unique domain sending at least one link to your site. If example.com links to you on five pages, that is still one referring domain. If five different domains each link to you, that is five referring domains. Backlinks count each link separately. Authority metrics like Ahrefs Domain Rating are built on referring domains, not raw link counts, because quality of sources matters more than volume.
For an expired domain, the referring domain count is the starting point. A domain with 120 referring domains is generally stronger than one with 80, all else equal. Quality matters: a link from a news site or industry publication is far more valuable than one from a low-quality directory. The count tells you how much diverse support the domain has.
How referring domains differ from backlinks and why it is more reliable
Referring domains measure breadth of support; backlinks measure link volume. A site can inflate backlinks by publishing many links on low-quality pages. Referring domains are harder to inflate because each site, regardless of link count, counts as one.
This makes referring domains more resistant to simple link-inflation tactics, though not immune: a network of sites can still create many referring domains. As a hypothetical example, a private blog network with 50 sites can send 1,000 backlinks, inflating the backlink count while contributing only 50 referring domains.
Backlinks become misleading when a few sites send many links. Imagine a domain that receives 500 links from five strong sites and one link each from 100 other sites. The backlink count is 600, suggesting strong authority. But the breakdown shows that the domain is heavily dependent on just five sources. If one of those five sites removes its links, the domain loses a large share of its backlinks and arguably much of its true authority. A referring domain count of 105 would more honestly represent the diversity of the domain's support.
Quality: which sites count
Not all referring domains contribute equally to authority. A link from Wikipedia or the New York Times carries far more weight than a link from a profile page on a free directory. A plain referring domain count does not weigh them: a referring domain is a referring domain. Metrics like Domain Rating add the weighting.
The way to assess quality is to look at the referring domains one by one or in aggregated form, including the strength of each one. Majestic's Trust Flow metric attempts to measure quality by looking at closeness to trusted seed sites. If a domain's referring domains are mostly high-DR sites from relevant niches, the referring domain count is a strong signal. If they are mostly low-DR sites or unrelated topics, the count is less meaningful.
You can also check whether referring domains are still active and still linking to the domain. Sites change owners, delete content, or remove links. A domain with 200 referring domains on paper might have noticeably fewer still actively linking to it. The Wayback Machine can show whether a linking page still exists and what it looked like.
Relation to Domain Rating: high DR from few domains is a warning
Domain Rating combines referring domains with their strength. As a hypothetical example, a domain with 50 referring domains might have a DR of 35, while another with 60 has a DR of 50. The difference reflects the quality of the linking sites. But sometimes the relationship breaks down, signaling problems.
High Domain Rating with few referring domains suggests those domains are very strong or the linking structure is artificial. A DR of 55 with only 40 referring domains should raise suspicion, while a DR of 28 with 200 referring domains is a more diversified profile. This comparison is a key check for spotting inflated domain rating.
As referring domains increase, DR tends to rise with them. A dramatic jump in DR without corresponding referring domains suggests authority came from one or two powerful links, which is less stable than distributed authority.
Lost referring domains
Domains that have changed owners or had their content removed often lose referring links. A site that shut down in 2015 may still show 180 referring domains from archived backlinks, but many of those links may now point to broken pages or redirects. When you re-register an expired domain, you inherit the referring domains in the sense that the links still exist on other sites. However, those links point to whatever you put on the domain now.
If the old domain was about auto repair and you turn it into a gardening blog, those 180 links provide no SEO benefit to you. The links are still technically referring domains in a metrics tool, but they are not relevant to your new content. Do not expect off-topic links to carry much weight for a site on a different subject.
The Wayback Machine does not show link counts, but you can open archived pages of sites that linked to the domain and see whether they have changed their content, removed the link or gone offline. A tool that shows referring domains over time is the better way to measure link decay.
Checking referring domains for free
Several free tools show referring domain counts. A site: search in Google tells you whether pages are indexed but does not directly show referring domains. WHOIS and domain lookup tools show basic registration information but not link data.
Ahrefs, Semrush and Majestic each offer some free lookups, but what the free tiers show changes, so check their sites for the current limits. That is often enough to get a sense of a domain's link profile.
The Wayback Machine is free and useful for the other half of the job. It does not count links, but it lets you open archived pages of the domain and of the sites that linked to it, helping you assess whether the links were real and are likely still active.
On hunter.domains, every listed domain shows core metrics including referring domains, and the free plan includes the full archive of ended domains. The Pro plan adds a detailed report per domain.
Frequently asked questions
How many referring domains is good?
There is no universal number; it depends on the niche and your goals. For an expired domain, a few dozen referring domains from relevant, quality sites is better than hundreds from junk, and a handful is weak unless they come from very strong sources. The benchmark is the competition: look up how many referring domains the sites ranking for your target keywords have, and compare quality as well as count.
What is a referring domain?
A referring domain is a unique website that contains at least one link to your site. It is counted once, regardless of how many links that website sends to you. If news.example.com, blog.example.com and shop.example.com all link to you, they may still be counted as a single referring domain if they are all subdomains of example.com.
Do 100 links from one site count as one?
Yes. If one website publishes 100 links to your site, they count as 100 backlinks but only one referring domain. The referring domain count highlights that all 100 links come from a single source, which is weaker than 100 links spread across 50 different domains.
