Open almost any SEO tool and you will see two numbers together: backlinks and referring domains. Because both describe links pointing to a website, it is easy to treat them as interchangeable. They are not. One measures individual links, while the other measures the unique websites those links come from. Understanding the difference helps you judge whether a link profile is diverse or inflated by repeated links from the same sources.
What Is a Backlink?
A backlink is an individual hyperlink on an external webpage that points to your website. If a blog post links to your homepage once, that is one backlink. If the same post links to two different pages on your site, most SEO tools will count two backlinks. Links can appear in editorial content, author biographies, resource pages, directories, navigation menus, footers, images, or other page elements.
Your backlink count is the total number of external links a crawler has found pointing to the site, folder, or page being analysed. That number can become very large when one website links to you repeatedly. A partner site might mention your brand across dozens of articles, while a sitewide footer link could appear on hundreds of pages. Each discovered link may increase the count even though every link originates from one website.
What Is a Referring Domain?
A referring domain is a unique domain that contains at least one backlink to your website. If example.com links to you once, it contributes one referring domain. If example.com links to you 100 times, it still contributes one referring domain, although it may contribute 100 backlinks.
This is why unique referring domains matter when evaluating link diversity. A site with 500 backlinks from five domains has 500 backlinks but only five referring domains. Another site with 100 backlinks from 80 domains has fewer links but much greater domain diversity.
Exact totals can vary between platforms. SEO tools use different crawlers, databases, update schedules, and rules for grouping or deduplicating links. Google Search Console groups linking sites by root domain in its Links report and combines certain duplicate links. Track trends within the same tool rather than expecting identical numbers everywhere.
Referring Domains vs Backlinks: The Core Difference
The simplest distinction is this: backlinks count links, while referring domains count sources. A single referring domain can generate one backlink or thousands of backlinks. Every counted referring domain, however, must provide at least one link.
A Practical Example
Imagine that three websites link to your business. A news site links to two articles, an industry directory links to your homepage, and a partner blog adds a sitewide link that appears on 200 pages. Your profile could show 203 backlinks but only three referring domains. The backlink total may look impressive, but it does not mean 203 independent websites have recommended you.
This gap is common when links come from sitewide templates, syndicated content, repeated author boxes, tag pages, or automatically generated pages. Reviewing both metrics prevents you from mistaking repetition for broad recognition.
Why Domain Diversity Often Deserves More Attention
Unique referring domains are commonly used as a quick indicator of link diversity. Links from multiple independent, relevant websites can show that your content or brand is being cited more widely. Another link from a domain that already mentions you may add less diversity than the first link from a new credible source.
That does not mean domain diversity should be pursued blindly. Ten links from respected websites relevant to your topic may be more meaningful than links from hundreds of low-quality, irrelevant, or spam-driven domains. A referring-domain total is a quantity metric, not a complete quality score. Relevance, editorial context, the strength of the linking page, and the overall pattern still matter.
Why Backlink Count Still Matters
Backlinks reveal details that a domain-level number cannot. You may want to know which pages attract the most links, whether an important article has lost citations, or whether one domain sends links to several resources. Backlink-level analysis also helps you inspect anchor text, source pages, target URLs, link attributes, and placement.
A high backlink count can be natural. Popular tools, studies, statistics pages, and established brands may earn repeated citations from the same publications. Editorial links from a relevant authority are not automatically a problem. Raw totals simply need context.
How to Evaluate Your Link Profile Properly
Start by comparing your backlink count with your unique referring domains. A large gap is not necessarily bad, but it is a reason to investigate the repetition. Check whether the extra links are editorial mentions, resource links, sitewide templates, duplicated pages, or low-value placements.
Next, assess the quality and relevance of the domains. Look for websites with a real audience, coherent content, and a genuine connection to your subject. Review which pages receive links and whether those destinations match your priorities.
Then look beyond the headline totals. A natural profile may include different types of websites, varied anchor text, links to several useful pages, and a mix of link attributes. Monitor new and lost domains over time so you can see whether your profile is expanding or relying too heavily on a small set of sources.
Which Metric Should You Prioritise?
For a quick high-level assessment, referring domains often provide the clearer view because they show how many unique websites link to you. This is especially useful when comparing link diversity with relevant competitors. Backlink count provides the deeper layer needed to understand link frequency, source pages, target pages, and repeated patterns.
Neither metric should be used alone. A strong analysis asks two questions: how many credible websites link to us, and what do the individual links from those websites look like? Together, those answers are more useful than chasing the biggest possible number.
Frequently Asked Questions
Can one referring domain provide multiple backlinks?
Yes. One domain can link to your website from one page or thousands of pages. It will normally count as one referring domain, while each discovered link may be counted separately as a backlink.
Are more referring domains always better?
No. More relevant and trustworthy referring domains can improve link diversity, but a large collection of weak, unrelated, or spammy domains is not automatically valuable. Quality and context should be reviewed alongside quantity.
Why do SEO tools show different totals?
Each platform has its own crawler, index size, update frequency, canonicalisation rules, and method for grouping duplicates or subdomains. Differences are normal, so use one consistent data source when monitoring progress.
Should I get another link from a site that already links to me?
It can still be worthwhile when the new link is editorially relevant, reaches a useful audience, or points to a different valuable page. However, a strong link from a new relevant domain may add more domain diversity than another repetitive placement.
Conclusion
Referring domains and backlinks describe different parts of your link profile. Backlinks show how many individual links have been found, while referring domains show how many unique websites provide them. Use domain diversity to understand the breadth of your recognition, and backlink-level data to examine link quality and behaviour. The healthiest goal is a growing profile of relevant, credible citations supporting useful pages on your site.
