The short answer
Key takeaways
- The gap is the set of referring domains that link to competitors but not to you — they’ve already proven they’ll link to pages like yours.
- Domains linking to several competitors at once are the strongest targets; one-off links are noise.
- Classify every opportunity (resource page, guest post, mention, directory, broken link) so the outreach angle is obvious.
- Prioritize by relevance × authority × winnability — not raw domain count — and keep acquisition strictly white-hat.
Your competitors’ backlink profiles are a map of links that are demonstrably attainable in your niche. If a site links to three companies that do what you do, it’s far more likely to link to you than a random prospect is. A backlink gap analysis — the “link intersect” — systematizes that idea: it isolates the domains linking to rivals but not to you, ranked by how many of them each domain links to. This guide is part of our backlink building cluster; here we cover finding and prioritizing the gap, then hand off to outreach.
How do I pick the right competitors to analyze?
Use SERP competitors, not aspirational brand rivals. The sites you actually compete with for links are the ones ranking on page one for your money keywords — they may not be the household names you’d list off the top of your head. Search your three or four most important terms, note the domains that rank repeatedly, and pick three to five that are close to your size and intent. A site ten times your authority has links you’ll never replicate; a peer’s link profile is a realistic shopping list.
How do I pull each competitor’s referring domains?
Open your backlink tool’s link-intersect or backlink-gap report, enter your competitors in one set of fields and your own domain in the “but not linking to” field, and export the referring domains (not individual URLs — you want one row per site). Work at the referring-domain level because a hundred links from one blogroll is one relationship, not a hundred opportunities. You’ll need a backlink data source for this step: Ahrefs, Semrush and Moz each maintain their own crawled link index and surface a near-identical report, and Google Search Console covers your own links for free. Larger indexes simply find more candidates; the method doesn’t change.
How do I find the overlap that matters?
Sort the export by how many of your competitors each domain links to. A site linking to one competitor is a maybe; a site linking to three or four — and not you — has all but told you it links to companies in your category. That multi-competitor overlap is the heart of the link intersect and where your first outreach hours should go. Domains that link to only a single rival can wait until you’ve worked the high-overlap rows.
How do I classify the link opportunities?
Each gap domain reached its link to your competitor somehow, and that “how” is your outreach angle. Visit the linking page and bucket it:
| Link type | What it looks like | Your outreach angle |
|---|---|---|
| Resource / “best of” page | A curated list your competitor is on | Show you belong on the list and ask to be added |
| Guest post / contributor | An author byline links back to the competitor | Pitch a genuinely useful article to the same outlet |
| Editorial mention | A journalist or blogger cited the competitor in prose | Offer better data, a quote, or an unlinked-mention nudge |
| Directory / listing | An industry or niche directory entry | Submit your own listing where it’s legitimately relevant |
| Broken-link opportunity | The linked page now 404s or has moved | Suggest your live equivalent as the replacement |
Broken links deserve their own pass — see broken link building for the full workflow of finding dead links on these domains and offering yourself as the fix.
How do I prioritize the list?
Don’t outreach top-to-bottom by domain authority. Score each opportunity on three axes and work the highest combined scores first:
- Relevance. Is the linking site genuinely about your topic? A relevant link from a modest site beats an off-topic link from a strong one.
- Authority. Does the domain carry real trust and traffic? Use it as a tie-breaker between relevant prospects, not as the primary filter.
- Winnability. Is there a concrete path to the link — a resource page you fit, a broken link to replace, a directory you qualify for? An achievable resource-page add outranks a long-shot pitch to a major publication.
A useful shortcut: relevance × winnability first, authority to break ties. That keeps your outreach hours on links you can actually earn this quarter.
How do I turn the gap into outreach?
With a classified, prioritized list, outreach writes itself: each link type maps to a specific angle, and each prospect already has a reason to link. Lead with the value you’re adding — a better resource, a corrected statistic, a working replacement link — not a generic “please link to us.” Personalize against the exact page you found, keep volume sane, and track replies so you can double down on the angles that convert. Our automated backlink outreach and cold email link building guides cover the sequencing and templates.
Keeping it white-hat
A gap analysis only tells you where to focus; how you acquire the link is what keeps you compliant. Earn links by being relevant and reaching out — that’s legitimate. Buying links, large-scale link exchanges, and automated link schemes violate Google’s link spam policies and pass risk rather than value. If a gap domain only links out because it sells links or runs a private blog network, skip it; the cost of a manual action or algorithmic discount far outweighs one link.
Sources & further reading
Keep reading
Pillar guide
Automated backlink outreach
How to scale link-building outreach without burning your domain — targeting, personalization at scale, deliverability, and the editorial links that still move authority in 2026.
Backlinks · How-to
Broken link building
The classic white-hat link tactic, updated for 2026: how to find dead links worth replacing, build the page that deserves the link, and pitch it so editors say yes.
AI Content · How-to
Content gap analysis
A step-by-step method to find the topics and queries your competitors cover and you don't — and turn the gaps into a prioritized, authority-building content plan.