Referring Domains vs Backlinks: What’s the Difference?

Open any backlink tool and you’ll see two big numbers: “backlinks” and “referring domains.” Beginners often focus on the bigger one — total backlinks — but the smaller one usually matters more. This guide explains the difference and which to actually track. For the wider picture, see our complete guide to backlinks.

The difference in one sentence

Backlinks count every individual link pointing to your site. Referring domains count the number of unique websites those links come from. So if one website links to you 50 times, that’s 50 backlinks but only 1 referring domain.

A simple example

Imagine three sites link to you: a news site links once, a blog links three times across different articles, and a forum links to you in twenty different posts. That’s 1 + 3 + 20 = 24 backlinks, but only 3 referring domains. The 24 sounds impressive, but the 3 is the more honest measure of how many distinct sources actually vouch for you.

Why referring domains matter more

To search engines, a link is a vote of confidence — and votes from many different sources are far more convincing than many votes from the same source. The tenth link from the same website passes much less additional value than the first; Google has effectively already “heard” from that site. Twenty links from one forum are nowhere near as powerful as twenty links from twenty different relevant sites.

This is why referring domains is usually the better headline metric for authority and for comparing yourself to competitors. It reflects how broadly the web endorses you, not how many times a few sources happen to link. It ties directly to the PageRank idea that diversity and breadth of endorsement signal genuine importance.

When total backlinks still tell you something

Total backlinks aren’t useless — they add context. Multiple relevant links from one strong, related site can still be valuable, and the ratio of backlinks to referring domains is itself informative. A profile with a huge backlink count but very few referring domains can be a red flag: it may mean sitewide links (like a footer link repeated across thousands of pages) or a spammy pattern, rather than broad, genuine endorsement. So look at both numbers together, but lead with referring domains.

What this means for your link building

• Prioritise new referring domains — a link from a site that’s never linked to you is worth more than another link from a site that already has.
• Value diversity — links from many different relevant sites beat many links from a few.
• Use the competitor-gap method on referring domains, not raw backlinks, when judging how many links you need (see how many backlinks you need).
• Don’t be impressed by big backlink counts alone — check how many unique domains they come from.

FAQ

What is the difference between backlinks and referring domains?

Backlinks count every individual link to your site; referring domains count the unique websites those links come from. Many links from one site equal many backlinks but one referring domain.

Which is more important for SEO?

Referring domains, usually. Links from many different relevant sites signal broader endorsement than many links from a few sources.

Is a high backlink count always good?

Not on its own. A huge backlink count from very few domains can indicate sitewide or spammy links rather than genuine, broad endorsement.

Should I track backlinks or referring domains?

Track both, but lead with referring domains — it’s the more meaningful measure of authority and the better basis for competitor comparison.

In summary

Backlinks count every link; referring domains count the unique sites behind them — and because diverse endorsement matters more than repetition, referring domains is usually the metric to lead with. Track both, prioritise new referring domains, and value diversity over raw counts. Read our complete guide to backlinks or get a free plan.