Subdomain Finder
Validation Error
Target Host Domain
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No active subdomains found in our common wordlist scan.
No active subdomains responded to DNS checks for this host.
Every domain tends to accumulate more subdomains than its owner remembers. A staging site here, a mail server there, an old marketing microsite nobody's touched in two years. This tool scans a root domain against a large dictionary of common subdomain prefixes and reports back only the ones that resolve to a live IP address right now.
That last part matters. There's no value in a list padded with dead entries. Every result you see here is actively responding, so the list stays short and genuinely useful rather than a wall of noise.
Automatically scan and discover hidden subdomains attached to any root domain name by checking against a massive dictionary of common prefixes.
Filter out stale data. The tool performs live DNS resolution to ensure that only subdomains actively pointing to a valid IP address are displayed.
An invaluable tool for security researchers and network administrators to map out a target's attack surface and find forgotten development or staging environments.
Common uses for a subdomain scan
- Auditing your own domain to see what's actually exposed
- Checking a domain before you buy it for forgotten staging or dev environments
- Security research and mapping a target's public attack surface
- Confirming a migration didn't leave old subdomains still pointing at a decommissioned server
No limits, no waiting
There's no cap on how many domains you can scan or how often. Run it as part of a one-off audit or make it a habit before you touch DNS on anything you're responsible for.
If a subdomain turns up that you weren't expecting, a DNS Lookup on it will show what it's actually pointing to, and a WHOIS Lookup on the root domain can help confirm who's responsible for it.
FAQS
What is a subdomain?
A subdomain is an additional part of your primary domain name. Subdomains are created to organize and navigate to different sections of your website (e.g., mail.example.com, api.example.com).
How does the Subdomain Finder work?
It checks a curated list of common subdomain prefixes (like blog, secure, staging, dev) against the entered domain. Each subdomain is queried in parallel via client-side requests, resolving DNS A-records in real-time.
Will it show inactive subdomains?
No, the Subdomain Finder only paints and displays subdomains that successfully resolve to an active IP address, keeping the results listing clean and actionable.
Is there a search limit?
There are no search limits. You can search as many domains as you like to scan for active subdomains.