Referring domains (also called linking domains or linking root domains) are unique domains that have at least one backlink pointing to your website. One domain can provide multiple backlinks, but it only counts as one referring domain.
Referring Domains vs Backlinks#
The Key Difference#
| Metric | What It Counts | |--------|----------------| | Backlinks | Every individual link to your site | | Referring Domains | Unique domains with at least one link |
Example#
If example.com links to you from 5 different pages:
- Backlinks: 5
- Referring domains: 1
Why the Distinction Matters#
Referring domain count often correlates better with rankings than raw backlink count because:
- It measures link diversity
- One domain, multiple links = diminishing returns
- More domains = more independent endorsements
- Harder to manipulate than link count
Why Referring Domains Matter#
Quality Signal#
More unique domains linking to you suggests:
- Broader recognition in your industry
- Content valuable enough for multiple sites to reference
- Natural link profile (harder to fake)
Ranking Correlation#
Studies consistently show referring domains correlate with rankings:
- Pages with more referring domains tend to rank higher
- The correlation often exceeds that of raw backlink count
- Google likely weights this as a quality signal
Link Profile Health#
Healthy link profiles have:
- Many referring domains
- Diversity of domain types
- Growth over time
- Relevant sources
Measuring Referring Domains#
Key Metrics#
Total referring domains: All unique domains linking to your site
New referring domains: Domains that started linking recently
Lost referring domains: Domains that stopped linking
Referring domain quality: Authority/relevance of linking domains
Tools#
- Ahrefs: Referring Domains report
- Semrush: Backlink Analytics
- Moz: Link Explorer
- Google Search Console: Limited linking site data
Many of these tools offer free tiers or trials. See our free backlink checker roundup to find the best option for tracking your referring domains without paying.
Referring Domain Quality#
Not All Referring Domains Are Equal#
Quality varies significantly:
High-quality referring domains:
- Relevant to your industry
- High domain authority
- Real traffic and audience
- Trusted, established sites
Low-quality referring domains:
- Irrelevant to your niche
- Spam or link farm sites
- No real traffic
- Recently created for link building
Quality vs Quantity#
Better to have:
- 100 high-quality referring domains than
- 1,000 low-quality referring domains
Focus on attracting links from authoritative, relevant sites.
Growing Referring Domains#
Why Domain Diversity Matters#
Diminishing returns: Multiple links from the same domain provide less incremental value than links from new domains.
Risk reduction: If one domain removes links or gets penalised, diverse profiles are more resilient.
Natural signals: Organic growth naturally produces domain diversity.
Strategies for Growth#
Content marketing: Create content that different sites want to reference
Outreach variety: Don't target the same sites repeatedly
Digital PR: News coverage from various publications
Community presence: Participate in industry conversations
Guest posting: Contribute to multiple relevant publications
What to Avoid#
Same domain obsession: Getting 50 links from one site won't help much
Link networks: Multiple domains owned by same entity don't count as diverse
Irrelevant domains: Quantity without relevance doesn't help
Referring Domain Velocity#
What Is It#
The rate at which you gain (or lose) new referring domains over time.
Why It Matters#
- Sudden spikes may appear unnatural
- Steady growth indicates healthy link building
- Decline may signal content or relationship issues
Natural Patterns#
New content: Temporary spike in new referring domains
Established content: Steady acquisition over time
Viral content: Larger spike, then plateau
Red Flags#
- Massive spike with no obvious cause
- Spike of low-quality domains
- Sudden loss of many referring domains
Analysing Competitors' Referring Domains#
Why Analyse#
- Find link opportunities (sites linking to competitors)
- Understand competitive landscape
- Set realistic targets
- Identify content gaps
What to Look For#
Referring domain count: How many unique domains link to them?
Domain overlap: Which domains link to multiple competitors?
Domain quality: What's the authority level of their referring domains?
Growth rate: How fast are they acquiring new domains?
Using Insights#
Sites linking to multiple competitors but not you = opportunities
Full guide: Competitor Analysis →
Common Questions#
How many referring domains do I need?#
There's no universal number. Analyse competitors ranking for your target keywords to understand your competitive landscape.
Is 1,000 backlinks from 10 domains good?#
Not great. That suggests concentrated links from few sources. Better to have fewer total backlinks from more domains.
Do subdomains count as separate referring domains?#
Typically yes—blog.example.com and example.com are counted separately by most tools. However, Google likely understands they're related.
Why did my referring domains drop?#
Possible reasons:
- Linking sites went offline
- Linking pages were deleted
- Tool data refresh
- Penalty to linking sites
Summary#
Referring domains are unique domains that link to your site:
Key points:
- More meaningful than raw backlink count
- Measures link diversity
- Correlates strongly with rankings
- Focus on quality over quantity
Growing referring domains:
- Create valuable content
- Diversify outreach targets
- Build relationships across industry
- Monitor growth over time
What to track:
- Total referring domains
- New vs lost referring domains
- Quality/authority of linking domains
- Comparison to competitors
Aim for steady growth in high-quality referring domains rather than chasing raw backlink numbers.