Referring Domains vs Backlinks: Which Number Actually Predicts Rankings
Referring domains vs backlinks: why 50 links from 50 sites beat 5,000 from one, what a healthy ratio looks like, and how to check both free.
Sathi··5 min read
Sathi
Founder, DidYouSEO
Coder turned marketer, now learning SEO in public and writing about it while building DidYouSEO.
Two sites each have 5,000 backlinks. One has links from 900 different websites. The other has links from 12, mostly sitewide footer links. On paper they look the same. In practice, one has a strong link profile and the other barely has one.
That's the difference between referring domains and backlinks. This guide explains both, why referring domains are the better signal, what a normal ratio looks like, and how to check them free.
Definitions
- Backlink: any single link from a page on another site to a page on yours. Every link counts separately.
- Referring domain: a unique website that links to you at least once. However many links it sends, it counts once.
If a blog links to you from 300 posts through its blogroll, that's 300 backlinks and 1 referring domain.
| Backlinks | Referring domains | |
|---|---|---|
| Counts | Every link | Every unique linking site |
| Easy to inflate? | Yes: one sitewide link adds thousands | Harder: each one is a separate site |
| What it tells you | Volume | Breadth of endorsement |
| Drives Domain Rating? | Barely | Yes |
Why referring domains matter more
Think of a link as a recommendation. Fifty different people recommending a restaurant tells you more than one person recommending it fifty times.
Third-party authority scores are built on the same idea. Ahrefs says only the first link from a domain increases DR, and additional links from the same domain don't move it further. Google doesn't publish its formula, but its spam policies single out patterns like large-scale link schemes and widely distributed footer links, which are exactly the patterns that inflate backlink counts without adding referring domains.
Referring domains also grow more slowly and steadily, which makes them a better trend to report. A spike of 4,000 backlinks in a week usually means one site added you to a sidebar, which is nothing to celebrate.
What a healthy backlinks-to-referring-domains ratio looks like
There's no ideal number, but these patterns are worth knowing:
| Ratio (backlinks ÷ referring domains) | What it usually means |
|---|---|
| 1–5 | Normal for most sites; links come from many places |
| 5–20 | Some sitewide links (partners, directories, a blogroll) |
| 20–100 | A few sites link from every page; check who they are |
| 100+ | One or two sitewide links dominate; the backlink count is misleading |
A high ratio isn't automatically bad. A partner linking from its footer is normal. It just means you should judge the profile by referring domains, not by the headline backlink number.
Which referring domains are worth having
Not all referring domains are equal. A useful one usually:
- Is relevant to your topic or industry
- Has real traffic, meaning people actually visit it, not just a high score
- Links editorially: a writer chose to link, rather than the link being sold or auto-generated
- Doesn't link to everyone: a site that links out to 10,000 domains passes very little to each
Ten referring domains that tick every box will help more than 200 directory listings.
How to check referring domains free
| Tool | What you get free | Limit |
|---|---|---|
| Google Search Console | Top linking sites and pages | Your own verified site only |
| Bing Webmaster Tools | Backlinks, plus comparison with up to two other sites | Needs a verified site |
| Ahrefs Backlink Checker | Referring domain count and top 100 backlinks for any site | Top 100 only |
| Moz Link Explorer | Linking domains and Domain Authority | Small monthly query cap |
| DidYouSEO | Domain Rating for up to 10 domains at once | DR score only, no link list |
For the full rundown, see our comparison of free backlink checkers.
How to find your competitors' referring domains
The most useful list in link building is the sites that link to two or three of your competitors but not to you. They've shown they link to sites like yours, so they're far more likely to say yes.
Free ways to build that list:
- Bing Webmaster Tools' comparison. Add up to two competitors and filter to domains that don't link to your site. That's the list, ready-made.
- Ahrefs' free backlink checker for each competitor. Note which referring domains appear for more than one of them.
- Search for your competitors' brand names in roundups and "best X" articles. Anyone who wrote one is a candidate to include you next time.
Then sort by relevance, not by authority score. A small, focused industry blog that links to all three competitors is a better prospect than a big generic site that linked to one of them once.
How to grow referring domains
The short version: earn links from many different relevant sites rather than many links from a few. Original data, free tools, genuine guest contributions on sites your audience reads, and turning unlinked brand mentions into links all add new referring domains. We go through each in how to increase Domain Rating.
Common mistakes
- Reporting backlink totals to clients. A jump from 2,000 to 9,000 backlinks looks impressive and may be one footer link. Report referring domains.
- Panicking about a backlink drop. If one site removes a sitewide link, you can lose thousands of backlinks and zero referring domains. Check before you worry.
- Chasing referring domains from irrelevant sites. Fifty links from unrelated directories add referring domains but little value. Relevance still matters.
- Comparing counts across tools. Every tool crawls a different slice of the web. Compare your numbers with competitors inside the same tool, never across tools.
If you're paying for a backlink tool only to check referring domains and authority, there are free options that cover most of that. See our honest comparison of free Majestic alternatives.
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