Backlink Gap
Updated July 21, 2026
Referring domains linking to competitors but not to you, identifying link-building opportunities.
Also known as: Link gap, Link gap analysis, Backlink gap analysis, Link Intersect, Competitor backlink gap
A backlink gap is the set of referring domains that link to one or more of your competitors but not to your own site. You find it by loading several backlink profiles side by side and subtracting yours from theirs, leaving a list of domains that have already linked within your niche but have not yet linked to you. The logic that makes the analysis worth running is simple: a site that links to two or three of your competitors has demonstrated editorial willingness to cover this space, which makes it a warmer, higher-probability outreach target than a domain you approach cold.
The technique is a mainstream, well-documented part of SEO practice rather than a term with a single named inventor. It emerged alongside the multi-domain backlink comparison tools that major platforms built, and most ship it as a named feature: Semrush calls it Backlink Gap, Ahrefs calls the same analysis Link Intersect, SE Ranking offers a Backlink Gap Analyzer, and seoClarity labels its version Link Gaps. Semrush's tool compares up to five domains at once and scores each opportunity by Authority Score, monthly visits, and how many of the compared competitors already carry the link.
Link builders, SEO teams, and competitive-intelligence analysts use it to turn a vague goal, earning more authoritative links, into a concrete prospect list ranked by likelihood of success. It answers a narrow, actionable question: which specific sites already vouch for my rivals, and how do I earn the same coverage.
How a backlink gap analysis works
You start by choosing three to five competitor domains that share your space, then load their backlink profiles alongside your own in a comparison tool. The tool intersects the profiles and returns the referring domains that link to at least one competitor but not to you. That intersection is the gap.
The output is not a single number but a specific list of domains and pages, which is what makes it operational. Most tools let you filter and rank it: by domain authority, by estimated traffic, and by the count of competitors a given domain already links to. That last signal matters most. A domain linking to a single competitor may be a one-off; a domain linking to three or four of them has an editorial pattern of covering this niche, so it sits at the top of the outreach queue. Practical guidance across the major tool documentation is to trim the raw intersection down to a manually reviewed shortlist, on the order of fifty to a hundred prospects, because relevance and link quality decide outreach success far more than raw prospect count.
Backlink gap vs. content gap analysis
These two are constantly conflated because vendors market them side by side. Semrush, for instance, bundles Backlink Gap, Keyword Gap, and Content Gap as separate tools in the same gap-analysis suite, and casual usage blurs them together.
They answer different questions. A backlink gap compares link profiles: which domains point to competitors but not to you. A content gap compares topics and keywords: which subjects or search terms competitors rank for or publish about that you do not. One produces a list of outreach targets; the other produces a list of pages to write. They are complementary: a strong content gap finding often explains why a competitor earns links you lack, since better coverage of a topic attracts more citations. But they are not substitutes. If a report is handing you referring domains to email, it is a backlink gap; if it is handing you keywords or article ideas, it is a content gap. Keeping the two separate prevents a common planning mistake: treating a link-acquisition problem as a content-production problem, or the reverse.
Turning the gap into an ongoing signal
Backlink gap analysis is usually run as a point-in-time audit, but the underlying data changes constantly as competitors earn new links. For a competitive-intelligence workflow, the more useful cut is the delta over time: not the full static gap, but the specific high-value links a competitor acquired since you last looked.
This reframes the exercise from a periodic SEO chore into a monitoring signal. A team tracking competitors' backlink profiles continuously can treat a newly earned link from an authoritative publication as an event worth reviewing: it may indicate a press push, a new partnership, a product launch that drew coverage, or simply a linkable asset worth studying. This is the angle a competitor-monitoring product like meertrack can take that a batch SEO report does not: surfacing the new referring domain as it appears, alongside the pricing-page, job-posting, and news changes it often accompanies, rather than waiting for the next manual audit to reveal it after the fact.
Common mistakes and limitations
The most common error is treating the raw gap list as a to-do list. The unfiltered intersection includes scraper sites, low-authority directories, and links you would never want or could never realistically earn. Skipping the manual review step wastes outreach effort on domains that will not move rankings.
A second mistake is comparing the wrong competitors. Pull in domains that are large but not actually similar to yours, and the gap fills with links that are irrelevant to your niche. The comparison set should be genuine search competitors, not just well-known brands. Finally, the analysis tells you where a link exists, not how it was earned. A competitor's link from a major publication may trace back to original research, a founder relationship, or a paid placement, contexts the tool cannot see. The gap identifies the target; understanding what would make that site link to you is separate work, and it is where the analysis stops being mechanical.
Stop looking terms up. Start tracking them.
meertrack watches your competitors' websites, pricing, and hiring, then alerts you when something meaningful changes.
Frequently Asked Questions
What is a backlink gap analysis?
It is the process of comparing your site's backlink profile against several competitors' profiles to find referring domains that link to them but not to you. The result is a ranked list of sites that already link within your niche, which become prioritized targets for a link-building outreach campaign. Tools typically let you compare three to five domains at once and sort the gap by authority and relevance.
What is the difference between a backlink gap and a content gap?
A backlink gap compares link profiles and returns referring domains that point to competitors but not to you: a list of outreach targets. A content gap compares topics and keywords and returns subjects competitors cover or rank for that you do not, a list of pages to create. Many SEO platforms sell both in the same suite, which is why they get conflated, but they produce different deliverables.
How many competitors should I compare in a backlink gap analysis?
Common guidance is three to five closely matched competitors. That range is wide enough to reveal domains that link to the niche as a whole rather than to one outlier, but narrow enough to keep the list relevant. The strongest opportunities are domains that link to multiple competitors at once, since a shared link pattern signals genuine editorial willingness to cover your space.
Is Ahrefs Link Intersect the same as a backlink gap?
Yes. Link Intersect is Ahrefs' product name for the same analysis other vendors call a backlink gap. It finds domains linking to competitors but not to your site. Semrush ships the feature as Backlink Gap, SE Ranking as its Backlink Gap Analyzer, and seoClarity as Link Gaps. The concept is identical across all of them; only the branding differs.
How do you find backlinks your competitors have that you don't?
Run a comparison tool that overlaps several link profiles at once: plug in your own domain along with a handful of rivals, and it surfaces every site linking to one or more of them while skipping you. From there, sort what comes back by authority, traffic, and the number of competitors each domain has already linked to, then hand-review the results down to a shortlist of realistic, on-topic prospects before you begin any outreach.
Related terms
Topics or keyword clusters competitors cover but are absent from your site.
Keyword Gap AnalysisIdentifying keywords competitors rank for but you do not, revealing content opportunities.
Domain Authority (DA) / Domain Rating (DR)Proprietary scores (Moz, Ahrefs) predicting how likely a domain is to rank. Used to benchmark competitive SEO strength.
Link VelocityThe rate at which a domain acquires new backlinks. A spike in a competitor's link velocity signals a PR push or campaign.
Competitive BenchmarkingSystematic comparison of processes, products, pricing, or performance against competitors to identify gaps and improvements.
Gap AnalysisComparing current performance to desired performance across key dimensions to identify "gaps" that strategy must close.
SERP Feature TrackingMonitoring which competitors appear in featured snippets, People Also Ask, knowledge panels for target keywords.
Cannibalization DetectionIdentifying when multiple pages on the same site compete for the same keyword, suppressing rankings.