Backlink Gap Analysis: Find Sites Linking to Competitors but Not You — and Filter Out the Noise
A backlink gap analysis lists sites that link to your competitors but not to you, the most direct way to find link opportunities. The raw list mixes in sitewide links, spam sites and competitor partners. How to run it and filter it, with real data for moz.com against ahrefs.com and semrush.com.
A backlink gap analysis lists sites that link to your competitors but not to you, the most direct way to find link opportunities. The raw list mixes in sitewide links, spam sites and competitor partners. How to run it and filter it, with real data for moz.com against ahrefs.com and semrush.com.
If a site links to two of your competitors but not to you, it is probably a directory, a list article, a tool roundup or press coverage, and you have a real chance of appearing there too. That is the logic behind a backlink gap (or link intersect) analysis.
1. Real Example: moz.com vs ahrefs.com and semrush.com
On 9 October 2026 we ran the backlink gap tool with moz.com as our domain and ahrefs.com and semrush.com as competitors: 13,820 domains link to both competitors but not to moz.com. The top results by domain rank:
| Referring domain | Rank | Links to ahrefs.com | Links to semrush.com |
|---|---|---|---|
| plumbersandhvacmarketers.com | 392 | 13,702 | 792 |
| expert-ia-seo.fr | 362 | 31,943 | 2,807 |
| peerpush.net | 351 | 23,967 | 5 |
| patrickstox.com | 349 | 18,714 | 26 |
| bebran.com | 315 | 55,927 | 3,587 |
| 60detiknewss.com | 305 | 4,645 | 273 |
2. Filter the Raw List First
The table shows the key problem: a domain sending tens of thousands of links to ahrefs.com is almost never citing it article by article. It is more likely to be:
- Sitewide links: a link in the footer, sidebar or template counts once per page. These carry limited value and are hard to replicate.
- Auto-generated pages: sites that scrape or stitch together SEO tool data; be wary of domains with news-style names and numbers (such as 60detiknewss.com).
- Partnerships: a personal blog linking heavily to one competitor may have a working relationship with that company. You are unlikely to win those links.
| Filter | Keep | Drop |
|---|---|---|
| Link count | A few to a few dozen links to each competitor | Thousands to one competitor (mostly sitewide) |
| Relevance | Related to your industry, language and market | Unrelated news and aggregator sites |
| Link type | Lists, reviews, resource pages, tool roundups | Footers, paid placements, comment sections |
| Feasibility | A clear way to submit, get listed or get in touch | Competitor partners, employees or affiliated sites |
3. After Filtering
- Open the linking page and see how competitors appear: on a "best tools" list, prepare a comparison of your product; on a resource page, offer a free tool or dataset worth listing.
- Start with sites linking to both competitors: they have already shown they link to sites like yours.
- Do not buy links: Google treats links bought to manipulate rankings as link spam.
Backlink Gap Tool
Enter your domain and one or two competitors to list domains that link to them but not to you, strongest first. One free check a day.
Referring Domains Checker
See the 50 strongest domains linking to any site.