Backlink Gap Analysis: How to Find and Close the Link Gaps Your Competitors Are Winning

By RankTree Team · 2026-09-18

Backlink gap analysis is the process of comparing your website's backlink profile against your competitors' to find the domains linking to them but not to you. 

Each of those domains is a potential outreach target, a site that already links to businesses like yours and could plausibly link to you too. 

It's one of the fastest ways to build a realistic prioritized link building list instead of guessing.

What Is Backlink Gap Analysis?

Search engines still treat backlinks as one of the strongest trust signals a page can earn. When a competitor outranks you for a keyword you're equally well optimized for the difference is often in the number and quality of referring domains pointing at their page not the content itself.

A backlink gap analysis (sometimes called a "link intersect" the term Ahrefs and Moz both use for this exact technique) pulls the backlink profiles of two or more competitors and finds the referring domains they share then subtracts the ones already linking to you.

What's left is your gap: real websites in your niche that already link out to companies like yours.

This is different from a general backlink audit which looks only at your own links. A gap analysis is inherently competitive it only exists in comparison to other sites.

Backlink Gap Analysis vs. Content Gap Analysis vs. Keyword Gap Analysis

These three terms get used interchangeably but they answer different questions and mixing them up wastes research time:

In practice the three feed each other: a content gap tells you what to write a keyword gap analysis tells you what to target and a backlink gap analysis tells you who to ask to link to it once it's published.

If you haven't run a content gap analysis yet do that first it directly shapes which pages are even worth building links to. (See our guide on Content Gap Analysis for the full process.)

Key Metrics You Need Before You Start Gap Analysis

Both major tools throw a wall of numbers at you. Here's what actually matters:

• Domain Rating (Ahrefs) / Authority Score (Semrush) / Domain Authority (Moz): A 0–100 estimate of a domain's overall link strength. Not a Google metric just a proxy for comparison.

• Referring Domains vs. Total Backlinks: 50 links from 1 site count far less than 50 links from 50 different sites. Always sort by referring domains not raw backlink count.

• Dofollow vs. Nofollow: Only dofollow links pass ranking signal directly; nofollow/sponsored/UGC links still have referral and trust value but don't count the same way in most tools' gap filters.

• Anchor Text: The clickable text of the link. Reviewing competitor anchor text patterns shows you how sites are naturally describing their content useful for your own outreach pitch.

• Link Intersect / Matches: How many of the competitors you entered are linked to by a given referring domain. A domain linking to 3 of your 4 competitors is a stronger more relevant target than one linking to just 1.

How to Do a Backlink Gap Analysis (Step by Step)

Step 1: Pick the Right Competitors

Don't just list brand rivals pull 3–5 sites that actually rank on page 1 for your target keywords. A "competitor" for gap analysis purposes is anyone Google already trusts for your topic whether or not you'd call them a business competitor.

Step 2: Choose Your Method

• Paid tools (Ahrefs, Semrush, Moz) run this as a built-in report and are fastest for ongoing use.

• Free/manual method: Export each competitor's referring domains from a tool's free trial or a limited free checker (Ahrefs' free Backlink Checker shows top links; Ubersuggest and Moz Link Explorer offer limited free lookups) drop them into a spreadsheet and use a simple formula (=COUNTIF or a VLOOKUP against your own list) to find domains that appear for competitors but not for you. Slower but works with zero budget.

Step 3: Run the Gap/Intersect Report

Enter your domain plus 2–4 competitor domains. Most tools let you compare root domain subdomain or exact URL match the level you're actually competing at (e.g. compare your blog subfolder to theirs not your whole domain to their whole domain if you're only building links to content pages).

Step 4: Filter for Quality Not Just Quantity

Set a minimum DR/Authority Score (start around 20–30 for most niches) exclude domains with very low or suspicious traffic and check topical relevance manually a high authority domain that's completely off topic is rarely worth pursuing.

Step 5: Segment Your List

Borrow the segmentation model most gap tools already use:

• Best: Links to all your competitors not you highest priority

• Shared: Links to you and competitors low priority already covered

• Unique: Links to only one competitor good but narrower opportunity

• Weak: Links to you less often than competitors worth strengthening

Step 6: Build Your Prioritized Outreach List

Rank by: relevance → authority → how many competitors they already link to → how recently the site published content (active sites reply faster).

A simple spreadsheet with these columns beats a cluttered tool export every time.

Example of what your final gap table might look like:

Best Backlink Gap Analysis Tools

Turning Gaps Into Real Links (Outreach)

A gap list is only useful if you act on it. Keep outreach short specific and non templated sounding:

Subject: Quick resource suggestion for [Page Title]

Hi [Name]

I came across your page on [topic] and noticed you link out to a few resources on [related subject]. I recently published a guide on [your topic] that covers [specific angle they don't mention] thought it might be a useful addition for your readers.

Here's the link if you'd like to take a look: [URL]

No worries either way and thanks for putting together a genuinely useful resource.

[Your name]

Personalize the bracketed parts every time generic mail merge outreach to a gap list gets ignored almost as fast as cold spam.

How This Fits Into Your Content Strategy?

Backlink gap analysis works best as the last step in a content pipeline not a standalone task:

1. Run a gap analysis to find underserved subtopics.

2. Write the piece using a proper content brief so it's genuinely more complete than what's ranking.

3. Only then run a backlink gap analysis you're now reaching out with something better than what the linking sites already point to which dramatically improves reply rates.

Skipping straight to outreach without first closing the gap is the single biggest reason link building campaigns underperform.

Common Mistakes to Avoid

• Chasing DR/Authority Score alone and ignoring topical relevance an off topic high authority link rarely moves rankings and can look unnatural.

• Comparing only one competitor. Three to five gives you overlap patterns you can't see with a single comparison.

• Treating the export as a finished list. Raw tool output always needs manual relevance and quality filtering.

• Never refreshing the analysis. Backlink profiles shift monthly; rerun the report at least quarterly.

• Skipping the disavow step when the same analysis surfaces obviously spammy links pointing at your own site.

Is Backlink Gap Analysis Still Worth It in 2026?

Yes with a caveat. Google's own Search Central guidance on link spam is explicit that links should be earned not manufactured at scale and that participating in link schemes (including some aggressive gap based outreach at volume) can trigger manual action. 

Used correctly, backlink gap analysis isn't about mass requesting links, it's a research method to find sites that are already inclined to link to content like yours so your outreach is relevant and welcome rather than spammy. 

That distinction is what keeps this tactic effective and safe long term.

FAQs

Is backlink gap analysis free?

You can do it manually with free tool tiers and a spreadsheet though paid tools (Ahrefs Semrush) make it faster and more accurate at scale.

How many competitors should I compare?

3–5 is the sweet spot enough to spot overlap patterns without diluting relevance.

What's a good number of gap domains to find?

There's no universal number; focus on quality over volume. Even 10–15 highly relevant high authority gap domains outperform 100 low quality ones.

How often should I rerun a backlink gap analysis?

Quarterly for most sites; monthly if you're in an active outreach campaign.

Does backlink gap analysis replace content gap analysis?

No, they're complementary. Content gap analysis tells you what to build; backlink gap analysis tells you who to tell about it once it's built.