SignalSumo
Backlink Gap Tool

Backlink Gap Tool: Find the Referring Domains Linking to Competitors, Not You

Compare your backlink profile against up to 3 competitors and see exactly which referring domains link to them but not you — plus what content earned those links and how many you need each month to close the gap.

Find My Link Gaps See a sample report

No credit card required. First gap comparison free on any plan.

yoursite.com Primary Project Domain
Gaps Detected
Domain DR Spam Links to Comp. Category
industryblog.com 54 2% 3 of 3 Industry News
toolsdirectory.net 38 6% 2 of 3 Directory
expertroundup.io 47 1% 2 of 3 Blog
118 referring domains found that link to your competitors but not you.
Domain Rating & Spam Score Insights
Top Earning Content Audit
Link Velocity Targets
Up to 3 Competitors

What is a backlink gap tool?

A backlink gap tool compares your backlink profile against up to 3 competitor domains and identifies referring domains that link to them but not to you. SignalSumo shows the Domain Rating, spam score, link attributes, and category for each gap domain, audits which competitor pages earned those links in the first place, and recommends a monthly link velocity target to help you close the distance.

Key Takeaways

  • A backlink gap analysis compares your referring domain profile against up to 3 competitor domains at once.
  • Each gap domain is shown with its Domain Rating, spam score, link type (dofollow/nofollow), and niche category.
  • The tool audits which specific competitor pages earned the most backlinks so you can reverse-engineer their strategy.
  • A monthly velocity target tells you how many new referring domains to acquire per month to close the gap.
  • Filtering by Domain Rating lets you prioritise high-authority prospects and skip low-value link farms.
  • Revisiting the same competitor group does not consume extra report credits — only a fresh comparison does.
Link Building Barriers

The easiest links to earn are the ones already linking to your competitors

Stop guessing where to focus your link outreach effort. Uncover competitor referral sources systematically.

Easy-win opportunities stay invisible

A site already linking to two of your competitors is a far easier outreach target than a cold pitch — but without a gap analysis, you'd never know it exists.

Outreach effort goes in random directions

Without a prioritized list, link building turns into guessing which sites might say yes.

There's no benchmark for "enough"

Without a velocity target, it's hard to know whether 5 new links a month is keeping pace or falling behind.

What earns links stays a mystery

Competitors' best-linked pages are a direct signal of what content attracts links in your space — and that signal is easy to miss.

Core Capabilities

A complete map of who's linking to them — and not to you

Unlock full insights into rival backlink strategies and target domains.

Referring Domain Gap Grid

See every referring domain that links to your competitors but not to you, ranked and ready for outreach.

Domain Quality Signals

Every gap domain comes with Domain Rating, spam score, link attributes, and category, so you can prioritize quality opportunities over volume.

Top Earning Content Audit

A tabbed breakdown of each competitor's top backlink-attracting pages, so you know exactly what kind of content is earning links in your space.

Link Velocity Targets

Get a recommended monthly target — for example, 5, 10, or 25 new referring domains — sized to the actual gap between you and your competitors.

Intersection Venn Visualization

See an interactive overlap chart of shared referring domains across your domain and your competitors, making the gap visually obvious.

Multi-Competitor Comparison

Run the gap analysis against up to 3 competitor domains at once, instead of comparing one at a time.

Smart Credit Usage

Re-viewing a cached gap analysis for the same competitor group is free. A fresh comparison on a new competitor group uses standard report credits, since it pulls new referring domain data.

Workflow

From your domain to a prioritized outreach list in four steps

Get a detailed map of prospective link targets in minutes.

1
Add your domain

Select the primary project domain you want to find link gaps for.

2
Add your competitors

Enter up to 3 competitor domains to compare against.

3
We find the gap

SignalSumo identifies referring domains linking to them but not you, with quality signals for each.

4
Get velocity targets & outreach list

See your prioritized gap domains alongside a recommended monthly link-building pace.

Live Sample

See exactly what a real backlink gap analysis looks like

Review illustrative outputs comparing SEO metrics and finding high-value backlink opportunities.

Intersection Venn Visualization

See shared and unique referring domains. Identify links where multiple competitors rank to prioritize high-converting resources.

Referring Domain Stats
212 shared referring domains · 118 unique to competitors · 64 unique to you
yoursite.com: 64 unique referring domains Competitors: 118 unique referring domains yoursite.com 64 unique Competitors 118 unique Shared 212
Link Velocity Recommendation

Recommended target: +10 referring domains per month to close this gap within 12 months.

Referring Domain Gap Grid
Domain DR Spam Score Links to Competitors Category
industryblog.com 54 2% 3 of 3 Industry News
toolsdirectory.net 38 6% 2 of 3 Directory
expertroundup.io 47 1% 2 of 3 Blog
Top Earning Content Audit
Page URL Referring Domains
/blog/ultimate-guide 84 referring domains
/free-template-pack 52 referring domains

Example output for a sample comparison. Your results will reflect your own domain and competitors.

Comparison

Why find gaps with SignalSumo instead of a spreadsheet — or a generic free tool

Stop cross-referencing complex data exports. Build links using a simple, unified checklist.

Feature SignalSumo Manual Backlink Spreadsheets Generic Free Tools
Gap detection Automatic, ranked by quality Requires manually cross-referencing exports Often limited to one competitor at a time
Content-source insight Top Earning Content audit included Not available Rarely included
Velocity recommendations Sized to your actual gap Not available Not available
Credit transparency Cached views free, fresh lookups cost credits N/A Often unclear or capped abruptly
Pricing

More backlink data as you grow

Every paid plan includes the full toolkit. Plans differ only in how much you can use.

Mid · $1/mo
15
backlink gap reports / month · 5 projects
Pro · $99/mo
35
backlink gap reports / month · 10 projects
Agency · $249/mo
75
backlink gap reports / month · 25 projects
See all plans → Start 7-day free trial →

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How to Use Backlink Gap Analysis in Your Link-Building Workflow

A backlink gap report is only as valuable as the outreach strategy it feeds. Here's a step-by-step workflow for turning gap data into actual referring domains.

1
Pick the Right Competitors

Compare yourself against sites that rank for the same keywords you're targeting — not the biggest brands in your industry. A DR 90 site will have referring domains you can't realistically earn. Choose competitors within 15–20 DR points of your site for an actionable gap list.

2
Filter by Domain Quality

Sort the gap list by Domain Rating and filter out anything with a spam score above 10%. Your outreach time is finite — prioritise DR 30+ domains linking to multiple competitors, as these sites clearly operate an editorial linking policy and are more likely to respond to genuine outreach.

3
Study the Top Earning Content

Before reaching out, understand why those referring domains linked to your competitors. Was it a data study? An ultimate guide? A free tool? The Top Earning Content audit shows you exactly which assets attracted the most links — giving you a content brief before you even write a word.

4
Set a Monthly Velocity Target

Use the link velocity recommendation to define a monthly target — not as an arbitrary goal, but as the minimum cadence needed to close the gap within a realistic timeframe. Tracking this number monthly keeps your link-building accountable against competitor momentum rather than an internal vanity metric.

What Makes a Referring Domain Worth Pursuing?

Not every domain in your gap list deserves outreach. Here's the scoring framework that separates high-value targets from noise:

Signal High Priority Medium Priority Skip
Domain Rating DR 50+ DR 25–49 DR <25
Spam Score <3% 3%–10% >10%
Links to competitors 3 of 3 competitors 2 of 3 competitors 1 of 3 only
Site category Industry publication, editorial blog General directory, roundup site Link farm, PBN, unrelated niche
Link type earned Editorial in-content dofollow Resource page, footer Comment, forum profile, nofollow-only
A Realistic Link-Building Sprint (30 Days)
Week 1
Run gap analysis. Filter and export top 30 target domains. Research the content that earned their links.
Week 2
Create or update the content asset. Match or improve what your competitors published to earn those links.
Week 3
Send personalised outreach to your top 30 targets. Reference their existing competitor link as proof of editorial fit.
Week 4
Follow up once. Re-run the gap analysis to measure new referring domains acquired vs. your monthly velocity target.

Frequently Asked Questions

A backlink gap tool compares your backlink profile against competitor domains and identifies referring domains that link to them but not to you, surfacing specific, addressable link-building opportunities.

You can compare your domain against up to 3 competitor domains in a single gap analysis.

Link velocity is the rate at which a domain acquires new referring domains over time. SignalSumo recommends a monthly target, such as 5, 10, or 25 new referring domains, based on the size of the gap between you and your competitors.

The Top Earning Content audit shows which pages on each competitor's site have attracted the most backlinks, organized by competitor, so you can see what kind of content is earning links in your space.

Re-viewing a cached gap analysis for the same competitor group doesn't use additional credits. Running a fresh comparison on a new competitor group consumes standard report credits, since it requires pulling new referring domain data.

Find the links your competitors have that you don't

Your first gap comparison is free. No card required.

Find My Link Gaps
Find My Link Gaps Free
Find My Link Gaps Free