A link gap analysis compares your website's backlink profile with your competitors' profiles to find the websites linking to them but not to you yet. Moz's guide calls it competitor link analysis, Semrush's documentation calls the tool Backlink Gap, and both describe the same comparison. A backlink is one hyperlink on another site pointing at yours. A referring domain is the unique website behind those links. A profile is the full set of links and domains pointing at a site.
The method works for a reason Moz's guide states plainly: a site that already links to your competitors has shown it's interested in your topic. If your content is better than what it links to now, you have a better-than-average chance of earning a link there too, and the authority that comes with it.
Operators now run the comparison as an agent workflow. One September workflow pulls backlinks for your site plus the top five competitors through a backlink data API, then has the model sort every referring domain into Quality, Questionable or Spam on three signals: domain rank, a third-party authority number for the linking domain; spam score, an estimate of how manipulative that domain looks; and outbound links, how many links leave the linking page. The ask at the end is every good link they have that you don't. Another runs the whole shape end to end: pull the backlinks, run the gap, audit the site for linkable assets (pages worth citing, such as guides, tools or data), research contact details for the target sites, and draft the pitch emails.
What Is Link Gap Analysis
A link gap is the difference between profiles: the referring domains that point at competitors and are missing from yours.
The standard run takes three steps, in both Moz's guide and Semrush's documentation. Pick a tool with a link-comparison feature. Enter your domain plus a few top competitors. Then filter for the domains linking to competitors but not to you, and reach out with a pitch fitted to the page. Moz's Link Intersect takes up to five competitors, and Semrush's Backlink Gap compares the profiles of up to five sites at once.
You Plus Five: How the Pull Runs
Start with the competitors you already lose to on the queries that matter. Moz's guide says two competitors is a good number for best results, and five is the ceiling in both tools. Semrush's tool suggests competitors when you click into an input field, and it accepts root domains, subdomains or single URLs in any combination, so you can compare one section of a big site against a whole smaller one.
Enter your domain in the first field and the competitors below it. The tool returns the referring domains sending links to the entered sites, one row per domain, with columns showing which of the entered sites each domain links to. Semrush adds an Authority Score for each referring domain, a compound quality metric, plus an estimate of its monthly visits. Moz's guide calls the domain-level result an aerial view of the content and links in your space: a way to see at a glance which outside sites publish relevant content and link to your rivals.
Which Gaps to Pitch First: Match Count
Sort by how many competitors a domain links to before you read anything else. Semrush's documentation exposes this count as Matches, the number of analyzed domains a referring domain links to. Domains that match several competitors are the popular link sources in the niche. Single-match domains link to only one rival.
A multi-match domain earns the first look, because several independent editors in the same topic already found it worth linking to. A single-match domain can still earn a place when its topic fits your page so closely that a reader would expect the reference.
Semrush's documentation groups the same table into five views for the domain you pick in the prospects control:
- Best: points to all of the entered competitors, and not to you.
- Weak: points to you less than to your competitors.
- Strong: points to you only.
- Shared: points to you and to your competitors.
- Unique: points to one specific domain only.
Start from Best, then work down the match counts inside it.
Expand a row to see new, lost and follow links per competitor, and use that split to drop dead ends before any contact. A domain whose links to your rivals were lost or removed is a weaker prospect than one whose links are current.
Domain or Page: When to Narrow to One Asset
Moz's guide describes running the comparison at two levels. Domain level keeps every page on each entered domain in scope, which suits the first sweep. Page level narrows the input to one URL on your side and specific rival URLs: set your entry to the exact page and the competitor entries to pages linking to any combination, and the output lists the specific URLs linking to those rival pages and not to yours.
Narrow to page level when one asset carries the pitch. Moz's guide illustrates it with a single article built to beat two rival URLs on one topic. At domain level, that list would be too broad. At page level, each prospect is tied to the exact rival page your new asset is meant to replace. When no single asset is ready, stay at domain level and let the overlap tell you which asset to build first.
What a Pull Returns per Referring Domain
Each row is a candidate to qualify. It names the referring domain and shows which entered domains it links to; the match count carries the priority, and the Best to Unique views show which side of the gap the domain sits on.
Qualify in this order before any contact:
- Topical fit. The linking domain publishes in your topic, and the linking pages sit inside relevant content. A domain that fails fit stays off the list, whatever its match count.
- Match depth. Multi-match domains go into the first outreach set, ahead of single-match ones.
- Currency. The new, lost and follow breakdown per competitor shows whether the rival links are still live.
- Quality. Authority, spam score and outbound links, the same three signals the agent workflow sorts on, decide whether a domain lands in Quality, Questionable or Spam.
Topical fit is also the one check you can make from outside any backlink tool. qequals doesn't return backlink data. It returns live Google results for a query, so a pull for your topic query shows whether a prospect's pages surface for it today.
Keep a missing domain on the pitch list only when its topic fits yours closely enough that a reader would expect the link. Then write the pitch against the exact rival page it links to now, and say what your page does better.
