Websites that live on the same server share the same IP neighborhood — and search engines notice. A Class C /24 subnet (the first three octets of an IP address, like 93.184.216.x) usually means the same machine or hosting provider. Our free Class C IP Checker takes up to 20 domains, resolves each one, and groups them by subnet so you can instantly see which sites are hosted together. No account needed.
SEOs use this for competitive intelligence: finding that a rival’s entire “network” of review sites sits on one server tells you exactly what you’re up against. Link builders use it to avoid getting links from sites that all share one IP — link networks leave this footprint. Buyers researching a website check whether it shares hosting with spammy neighbors that could drag down trust.
Domains that scatter across many different subnets are independently hosted; domains that cluster onto one or two subnets share infrastructure. Skipped entries are simply domains that failed validation or could not be resolved — check their spelling and re-run.
Class C IP Checker
Enter up to 20 domains (one per line) and see which ones share the same Class C /24 subnet.
How to use
- Enter up to 20 domain names, one per line.
- Click “Check Subnets”.
- Review the subnet groups — each shows its /24 range and member domains.
- Domains in the same group share a Class C neighborhood.
- Check the skipped list for entries that failed validation or DNS resolution.
FAQs
What does it mean if two sites share a Class C subnet?
They resolve to IPs whose first three octets match, which almost always means the same server, VPS or hosting provider. It does not prove the same owner — shared hosting puts thousands of unrelated sites on one IP range.
Why were some of my domains skipped?
Entries are skipped when they are not valid domain names or when they cannot be resolved to an IP address — for example, expired, parked or mistyped domains. Fix the spelling and run the check again.
Can this prove two sites are owned by the same person?
No — it shows shared hosting, not shared ownership. Combine it with WHOIS data (registrar and creation dates) and content similarities for stronger evidence.