Every page ranking above you on the search results you care about got there for a reason. Some of that reason is content, some of it is technical, and a large part of it is the set of other websites vouching for them through links. Competitor backlink analysis is the discipline of reverse engineering that last part: pulling apart who links to your rivals, working out which of those links you could plausibly earn too, and turning that list into an outreach plan. Done well, it is the closest thing link building has to a shortcut, because someone else has already done the work of proving which sites in your niche are willing to link out.

The appeal is obvious. Instead of guessing at prospects from a blank page, you start with a proven list. If a resource page, a journalist, or an industry blog has already linked to three companies that do what you do, the odds they will consider you are far higher than for a cold prospect picked at random. That is the core insight behind the approach, and why the two dominant SEO platforms both built dedicated features around it.

This guide walks through the full workflow the way an agency actually runs it: choosing the right competitors, exporting their referring domains, using the link gap concept to surface sites that link to several rivals but not to you, filtering for quality, prioritising the links you can realistically replicate, and reaching out. We will be specific about what the tools genuinely do and clear about the one thing you should never try to shortcut: earning the link itself.

What competitor backlink analysis actually is

At its simplest, competitor backlink analysis is the practice of examining the backlink profiles of the sites you compete with in search, then using what you find to shape your own link building. A backlink profile is the collection of external pages that link to a website, along with the domains those pages sit on. When you analyse a competitor’s profile, you are looking at the referring domains sending them links, the pages earning those links, and the context in which they appear.

This is useful because links are not evenly distributed across the web. Willingness to link tends to cluster by topic, so a competitor who ranks well has, almost by definition, accumulated links from the pockets of the web that care about your subject. Reading their profile gives you a curated map of those pockets and saves the slow work of discovering them one prospect at a time.

It helps to separate this from a couple of adjacent activities. It is not the same as reviewing your own link profile for problems and gaps, which is an internal exercise. Nor is it simply admiring how many links a rival has. The point is not the number; it is the specific domains you could approach. Total backlink counts are a distraction, because a single site can link to a competitor thousands of times and inflate that figure without representing one new prospect. Referring domains, the count of unique linking websites, is the number that maps to real opportunity, and it also matters most for rankings: in Backlinko’s analysis of 11.8 million search results, the number of domains linking to a page correlated with rankings, and links from a diverse group of different sites appeared to matter more than piling up links from the same handful of places.

One framing to fix from the start: the analysis is reconnaissance, not the campaign. It tells you where the doors are; it does not open them.

Find your true search competitors first

The most common mistake happens at step one: people analyse the wrong competitors. Your business competitors, meaning the companies your sales team names in deals, are not necessarily your search competitors. A large incumbent might dominate your market commercially yet earn its traffic almost entirely from brand searches and paid channels, which makes its backlink profile a poor template. Meanwhile a scrappy publisher or niche blog you have never pitched against might own the exact informational queries you are trying to rank for.

Your true search competitors are the domains that consistently appear in the results for the keywords you want. The practical way to find them is to look at overlap in ranking keywords rather than market share. Both major platforms have a competing domains view that ranks other sites by how many of your target keywords they also rank for, and that list is usually more honest than your assumptions. If a site shares hundreds of your priority keywords, its links are relevant regardless of whether you have ever thought of it as a rival.

A sensible shortlist is three to five domains, with a mix. Include at least one direct commercial competitor, one strong content-led site in your space, and one aspirational domain that ranks above everyone. The content-led site in particular tends to surface the richest seam of editorial prospects, because it earned its links precisely by being link-worthy.

Be wary of picking competitors wildly out of your league. A campaign you can act on this quarter comes from studying peers roughly one or two steps ahead of you, not ten, whose profiles are full of prospects you can realistically convert.

Pull the referring domains: Site Explorer and the backlink report

Once you have your shortlist, the first hands-on task is to export each competitor’s referring domains. In Ahrefs this lives in Site Explorer, positioned as a way to see which websites link to competitors and to gauge the quality of their backlinks across an index the company reports at 35 trillion live backlinks. In Semrush the equivalent is Backlink Analytics, drawing on a database the company describes as more than 43 trillion backlinks and 390 million referring domains, refreshed at least hourly. The figures matter less than the point they illustrate: no single index captures the entire web, so serious analysts often cross reference both.

When you open a competitor in Site Explorer, do not start with the raw backlinks report, which lists every individual link and is dominated by repetition. Start with referring domains, then sort and filter. Ahrefs offers a Best links filter designed, in its own words, to help you find valuable links in seconds by cutting through backlink noise, and that is exactly the mindset to bring: you are hunting for domains that represent a real, ideally editorial, endorsement rather than a boilerplate mention.

As you scan a competitor’s referring domains, patterns emerge quickly. You will see the same kinds of sites recurring: industry directories, resource pages, roundup posts, guest contributions, digital PR pickups, and genuine editorial citations. Learning to recognise these categories is half the value of the exercise, because each maps to a different link building tactic. A resource-page link is won very differently from a press pickup, and spotting which is which up front saves wasted outreach.

It is also worth studying which of a competitor’s own pages attract the most links, which Ahrefs frames as getting link-worthy content ideas from a competitor’s most linked-to pages. If one guide or tool or piece of original research is pulling in the bulk of a rival’s referring domains, you have learned what kind of asset earns links in your niche, which is the raw material for a data-led piece worth building on and improving.

The link intersect concept: the heart of the method

Exporting one competitor’s domains is useful. Comparing several at once is where the method becomes genuinely powerful, and that comparison is what the industry calls link intersect or a backlink gap. The logic is simple: if a single website links to three or four of your competitors but not to you, it is almost certainly a site that is receptive to companies in your category, has some editorial or listing reason to link out, and has simply never encountered you. That is the highest probability prospect you can find.

Ahrefs built this into its Link Intersect tool, which it describes plainly as a way to find the sites linking to your competitors but not to you. Its own documentation leans on a nice piece of intuition: if a site is linking to every one of your competitors, what are the odds it will link to you too, once it finds out you exist. The tool also surfaces the recurring linkers, the fans who link to almost everything a competitor publishes, who are among the warmest prospects on the list.

Semrush offers the same concept through its Backlink Gap tool, which lets you enter up to five competitors to see what referring domains you have in common with them, then isolate the domains you are missing. Its guidance is to review the Authority Score column to build a list of opportunities with the highest potential SEO impact, and to filter by metrics like traffic, category and authority. In practice you include your own domain in the comparison so the tool subtracts the links you already hold and shows only the true gap.

The output of either tool is the deliverable that makes this exercise worth doing: a list of named domains that link to your rivals, with your own links filtered out and each domain ranked by how many competitors it links to. A domain linking to four of your five competitors sits at the top; one linking to only one sits lower. That ranking is your rough priority order before you have even looked at quality, because breadth of linking signals both relevance and willingness.

Filter for quality, because most of the list is not worth your time

A raw intersect export flatters to deceive. It will contain scrapers, low quality directories, expired domains repurposed for spam, syndicated footers, and a long tail of sites you would never want a link from. Pouring outreach into that list wastes effort and, at worst, chases links that carry no value or actively signal manipulation. Filtering is not an optional polish step; it separates a useful campaign from a busy one.

Start with relevance, which no metric fully captures. A link from a site your prospective customers actually read is worth several from generic domains with impressive scores but no thematic connection. This is where human judgement beats automation: you can tell in seconds whether a site is a real publication or a thin link farm.

Then layer on the quantitative filters the tools give you. Authority-style metrics such as Ahrefs Domain Rating or Semrush Authority Score are a useful first pass to remove the obvious junk and sort what remains, and traffic estimates help confirm a site has real readers. But treat these as filters, not as the goal. The attributes that make a link genuinely valuable, namely editorial placement, topical relevance, real audience and a natural context, are only partly visible in any single number. Use the metrics to shrink the list, then read the actual pages before you commit outreach time.

One category deserves special caution. If you notice a cluster of a competitor’s links that all look paid, templated, or artificially placed, do not treat them as a template to copy. Google’s own spam policies define link spam as creating links to or from a site primarily for the purpose of manipulating search rankings, listing bought links and link exchanges among the examples. Google is explicit that buying and selling links is a normal part of the web for advertising, and that such links are fine as long as they are qualified with a rel nofollow or rel sponsored attribute. That is the point: those qualified links pass no ranking credit, so replicating them buys you nothing, and copying the unqualified versions simply borrows a competitor’s risk.

Prioritise the links you can actually replicate

A filtered list of relevant, quality domains is still not a plan until you sort it by how winnable each link is. Replicability depends almost entirely on why the link exists: some links were given for reasons you can recreate on demand, while others depend on relationships, budgets, or events you cannot reproduce this quarter. Sorting by that difference is what turns analysis into an efficient campaign.

The most replicable links are tied to a repeatable format. If a competitor earned a link from a curated list of tools or companies, you can pitch for inclusion in the same list. This is classic resource page prospecting, and an intersect export is one of the best ways to find such pages at scale, because resource pages tend to link to several competitors at once and so rise to the top of the gap list. Similarly, if a rival’s link comes from a contributed article, a well-judged guest contribution on the same publication is a clear path to a comparable placement.

A second highly replicable category is links pointing at content assets. When a competitor’s most linked page is a study, a calculator, an original dataset, or a definitive guide, the winnable move is to build something at least as good and then earn the same citations. Here you are not guessing what deserves links; you are looking at proof. Some of these opportunities also overlap with reclaiming links from unlinked brand mentions and moved pages, among the fastest wins because the linking site has already shown intent.

Broken links on a competitor’s referring pages are a further seam worth checking. If a page that links to a rival also contains a dead link, suggesting your resource as the replacement gives the site owner a reason to act that benefits them, not just you. Less replicable, by contrast, are one-off press pickups, links from long-standing partnerships, and coverage won through large-scale campaigns and media relationships. Log these as long-term ambitions rather than letting them sit at the top of a list you intend to execute soon.

A simple way to keep this honest is to tag every prospect with a tactic and a rough effort level as you triage, so the campaign that emerges is sorted by return on effort rather than by how impressive the linking domain looks. The most authoritative domain on your list is not the right first target if the only way a competitor earned its link was through a relationship you lack.

Turn the list into outreach

With a prioritised, tagged list in hand, the actual link building begins. This is the part no tool can do for you, and where most competitor-informed campaigns succeed or quietly stall. The advantage of working from an intersect list is that your outreach is never truly cold. You already know the site links to companies like yours, roughly what kind of link it gives, and often which page would host it. That context lets you write a genuinely relevant, personalised pitch rather than a generic template, and relevance is the single biggest driver of reply rates. A message that references the exact resource page a rival appears on, and explains why your inclusion would improve it for readers, beats a mass mail merge every time.

Sequence outreach by the priority order you built. Start with the warmest, most replicable prospects, the resource pages and roundups where inclusion is a low-friction ask, and use early wins to refine your messaging before harder targets. Keep the anchor text natural and varied across the links you win; over-optimised, repetitive anchors are a classic footprint of manipulation, and there is a whole discipline to getting anchor text right worth respecting.

Finally, treat competitor backlink analysis as a repeating cycle rather than a one-off project. Competitors keep earning links, and rerunning your intersect analysis every quarter surfaces the fresh domains they have picked up since you last looked, which are often the most receptive prospects. Tie the effort back to outcomes you can measure: tracking the metrics that show whether links are moving rankings and traffic keeps the programme accountable and tells you which competitor profiles are worth mining again.

Honest limits of the method

Competitor backlink analysis is powerful, but it is not magic. The first limit is data coverage. No backlink index sees the entire web, and different tools report different links for the same site, so any export is a large sample rather than a complete census. That is a good argument for cross referencing tools when a decision matters, and for not treating an absent link as proof it does not exist.

The second limit is that replicability is often lower than the list makes it look. A competitor’s most valuable links frequently come from things you cannot easily copy: a founder’s personal network, a moment of newsworthy timing, a budget for original research, or years of accumulated brand trust. You can see the link; you cannot always see the underlying advantage that produced it. Reading a profile with that scepticism keeps the campaign realistic.

The third and most important limit is the one this guide keeps returning to: the analysis tells you where to knock, but it does not give anyone a reason to open the door. A link is still an editorial decision made by a real person, and no export changes that fact. The teams that get the most from this method pair a sharp prospect list with genuinely link-worthy content and a respectful, relevant pitch. It is worth sitting the technique inside a broader plan rather than treating it as the whole strategy; our end-to-end walkthrough of building links the durable way puts competitor analysis in its proper place as one high-leverage input among several. Used that way, it is one of the most efficient starting points in all of SEO. Used as a shortcut around the hard part, it simply produces a longer list of people who will not reply.

Frequently asked questions

Is competitor backlink analysis legal and allowed by Google?

Yes. Studying which sites link to your competitors is a standard, legitimate research activity, and the major SEO platforms exist to enable it. What matters is what you do next. Using the insight to earn genuine, editorially given links is entirely within Google’s guidelines. Using it to buy or manufacture links that pass ranking credit crosses into what Google’s spam policies call link spam, so the analysis is fine; the temptation to copy manipulative links is the part to avoid.

How many competitors should I analyse at once?

Three to five is the sweet spot for an intersect analysis. Fewer than three gives you too little overlap to identify the domains that link across multiple rivals, which are your best prospects. Many more than five and the shared list becomes cluttered with domains that only one competitor happens to have. Both Ahrefs Link Intersect and Semrush Backlink Gap are built around comparing several competitors at once, with Semrush supporting up to five domains in a single comparison.

What is the difference between backlinks and referring domains, and which should I focus on?

Backlinks count every individual link, so one site can contribute hundreds of them. Referring domains count unique linking websites, so that same site counts once. For competitor analysis, referring domains is the more meaningful number, because each unique domain represents a distinct prospect and a distinct editorial decision. Backlinko’s analysis of 11.8 million results found that the number of domains linking to a page correlated with rankings, which is why diversity of linking sites tends to matter more than raw link volume.

Do I need both Ahrefs and Semrush to do this properly?

No, either one is enough to run the full workflow, and both offer a dedicated intersect or gap feature plus a deep backlink explorer. That said, because no index captures the entire web, agencies that need maximum coverage sometimes run the analysis in both and merge the results. If you are choosing just one, pick based on the wider toolset you will use day to day rather than on the backlink feature alone, since the core competitor analysis capability is comparable across both.

How often should I repeat a competitor backlink analysis?

Quarterly is a reasonable cadence for most sites. Competitors keep earning links, so rerunning your intersect analysis surfaces the domains they have acquired since your last review, and those recent links often point to the most active and receptive prospects. If a competitor launches a major campaign or a piece of original research, it is worth an ad hoc check sooner, because a sudden spike in their referring domains usually reveals a fresh, targetable pattern.