Inspiration
Businesses often publish valuable content across subdomains—product launches, documentation, campaign pages, events, support portals, and regional sites. But those subdomains are not always represented in the main website’s sitemap.
That creates a simple question: what valuable parts of a company’s web presence exist but may be invisible to its published SEO inventory?
SEO Gap was built to make that difference visible.
What it does
SEO Gap discovers subdomains associated with a domain and compares them with the URLs and hosts represented in the website’s sitemap.
It highlights subdomains that exist but appear to be missing from the published sitemap inventory, helping teams identify potential SEO gaps such as forgotten product sites, documentation portals, campaign pages, and legacy properties.
Instead of manually comparing DNS records, subdomains, and sitemap files, SEO Gap turns the process into a simple audit.
How we built it
SEO Gap combines domain infrastructure data with web and SEO analysis.
The application uses the Name.com Domain API to work with domains and DNS records, including creating and inspecting subdomains during the demo.
The backend collects discovered subdomains, retrieves sitemap information from the main website, normalizes the hostnames, and compares the two sets.
The result is presented as an actionable list of subdomains that may deserve further SEO investigation.
The application is designed around a simple pipeline:
Domain → Subdomain discovery → Sitemap discovery → Hostname comparison → SEO gap report.
Challenges we ran into
One of the biggest challenges was separating a DNS-level discovery problem from an SEO problem.
A subdomain existing does not automatically mean that it should appear in a sitemap, and being absent from a sitemap does not necessarily mean that search engines cannot discover it. We therefore had to frame the result as a potential SEO gap, rather than claiming that every missing subdomain is an SEO problem.
We also had to work through real-world DNS behavior, custom hostnames, subdomain configuration, certificate validation, and the differences between sandbox domains and domains that can be demonstrated publicly.
Another challenge was deciding how much infrastructure information to expose while keeping the final experience understandable to someone interested primarily in SEO.
Accomplishments that we're proud of
We turned a fairly technical comparison between DNS infrastructure and sitemap data into a simple, understandable SEO audit.
We are particularly proud that SEO Gap connects two areas that are normally treated separately: domain infrastructure and search visibility.
The project can uncover parts of a company’s web footprint that may otherwise require manually searching DNS records, sitemaps, and individual websites.
We also built the project around a real domain workflow rather than treating the domain API as an isolated demonstration.
What we learned
We learned that a company’s actual web footprint can be significantly larger than what is visible from its primary website or sitemap.
DNS data can therefore provide useful context for SEO analysis.
We also learned that sitemap absence should be treated as a signal rather than a conclusion. Search engines have multiple ways to discover pages, so the most useful product is one that identifies areas worth investigating instead of presenting every difference as an error.
Working with the Name.com Domain API also gave us a better understanding of how domain management, DNS records, subdomains, and application-level services fit together.
What's next for SEO Gap
The next step is to move from identifying missing subdomains to determining which gaps actually matter.
SEO Gap could crawl discovered subdomains, detect indexability, inspect robots.txt and canonical tags, check whether pages appear in search results, and estimate the amount and quality of content on each property.
We also want to classify discovered subdomains into categories such as documentation, products, support, campaigns, regional sites, and abandoned infrastructure.
Eventually, SEO Gap could become a continuous monitoring tool that alerts teams when new subdomains appear, valuable properties disappear from sitemap coverage, or DNS and SEO inventories drift apart.
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