Backlinks are still an important part of SEO, but simply being told to “build more links” doesn’t give you a useful strategy. The real question is: which websites should you target?
That’s where backlink gap analysis becomes useful.
The basic idea is straightforward: compare your backlink profile with your competitors and identify domains that link to them but don’t link to you. These domains can be valuable prospects because they’ve already shown that they’re willing to reference websites in your niche.
The Manual Approach
You can do this manually by exporting backlink data from an SEO tool, importing the files into a spreadsheet, and using formulas such as VLOOKUP or INDEX-MATCH to identify domains that appear in your competitors’ profiles but not yours.
It works, but it gets tedious quickly.
If you already have your backlink data in CSV files, you can automate the basic comparison with Python:
import pandas as pd
def find_gaps(your_file, competitor_file):
you = pd.read_csv(your_file, usecols=["Domain"])
competitor = pd.read_csv(competitor_file, usecols=["Domain"])
your_domains = set(you["Domain"].str.lower().dropna())
competitor_domains = set(competitor["Domain"].str.lower().dropna())
gaps = competitor_domains - your_domains
return sorted(gaps)
opportunities = find_gaps(
"my_links.csv",
"competitor_links.csv"
)
print(f"Found {len(opportunities)} opportunities")
for domain in opportunities[:20]:
print(domain)
This gives you a clean list of domains that appear in the competitor's backlink profile but not yours.
The code isn't really the difficult part, though. The quality of your backlink data matters much more.
A Faster Way to Find the Gaps
If you don't want to spend time exporting CSVs and comparing spreadsheets, I've been using the https://serpspur.com/tool/backlink-gap/ from SERPSpur for this type of workflow.
You enter your domain and competitor domains, and the tool compares their referring domains to identify websites you're missing.
One useful part is being able to prioritize opportunities instead of treating every backlink equally. A relevant, authoritative publication is usually a much better prospect than a random low-quality directory.
For example, during a recent analysis, I found a niche technology publication that was already linking to several competitors but had no link to my site. That immediately gave me a potential outreach target.
How I Use Backlink Gap Analysis
My workflow is fairly simple:
Run a backlink gap analysis against several competitors.
Export or record the most relevant missing domains.
Prioritize sites based on relevance and authority.
Research the pages where competitors earned their links.
Create a personalized outreach pitch.
Track the prospects and follow up.
I usually focus on the top 20–30 realistic opportunities rather than trying to contact hundreds of domains at once.
And the outreach matters.
Don't send a generic message saying:
“Can you please link to my website?”
Instead, explain why your content would actually be useful to their audience. If you have a newer statistic, original research, case study, or better resource, mention that specifically.
Backlink Gaps Are More Useful Than Random Link Building
The biggest advantage of competitor backlink analysis is that you're not starting from zero.
You're looking at websites that have already demonstrated some willingness to link to businesses or content in your space.
That doesn't guarantee they'll link to you, but it gives you a much more qualified prospect list than blindly searching for websites.
If you're already using tools such as Ahrefs or Semrush, you can perform this analysis there as well. For smaller projects, though, a lightweight backlink gap workflow can be enough to uncover some surprisingly good opportunities.
The goal isn't to build the most backlinks. It's to find the right websites and give them a genuine reason to mention your content.
Top comments (1)
Great breakdown of the workflow. The Python script is a solid fallback, but you hit the real bottleneck: data quality and time spent wrangling CSVs. If you're already using SerpSpur, here’s a tip to make that monthly gap analysis even more actionable.
Don't just export the raw missing domains. Filter by domain authority first, then cross-reference with a simple content relevance check. A DA 50+ site about digital marketing linking to a competitor is worth ten random DA 20 blogs. In the tool, sort by DA descending, then manually scan the top 30 for topical fit. That's your outreach list—nothing else.
Also, set a recurring reminder to run this on the 1st of every month. Link profiles shift weekly; competitors pick up new mentions, and old ones drop. A monthly cadence keeps your pipeline fresh without constant overhead.
One more thing: when you find that niche tech publication, don't just pitch your page. Use the tool's filter to see if they link to any resource pages or "best tools" listicles. If they do, offer a specific update—like a newer stat or a missing category—that makes their page better. That's how you turn a gap into a conversion.
The tool handles the comparison, but your edge is in the curation and the pitch. Keep it lean, prioritize by DA, and always personalize.