Subdomain discovery used to mean spinning up a Linux box, installing tools like Amass or Subfinder, and babysitting a terminal for hours. If you work in security, SEO, or competitive research, you've been there.
We built a simpler way.
What are subdomains and why do they matter?
Every domain can have dozens — sometimes hundreds — of subdomains. Things like api.example.com, staging.example.com, admin.example.com, mail.example.com. These subdomains often expose forgotten services, unsecured endpoints, or legacy apps that never got taken down.
For security professionals, this is recon 101. For SEO analysts, it reveals how a competitor structures their web presence. For IT teams, it's a way to audit your own attack surface before someone else does.
The problem is that most subdomain tools require self-hosting, technical setup, or a full security toolchain. That's a barrier for a lot of people who just need the data.
What the Real Subdomain Finder does
The Real Subdomain Finder is one of our tools at One Scales — available on Apify and ready to run in your browser with no installation required.
You give it one domain or a list of domains, hit start, and it returns every subdomain it can find. For each subdomain it also:
- Checks whether the DNS resolves — meaning there's a live server pointing to it
- Visits the page and pulls the title tag if a server is found
- Reports whether the page returns a 200, a redirect, or a 404
- Exports all results to JSON, CSV, or Excel
- Supports API and MCP access for integration into your own workflows or AI systems
Who this is for
- Security researchers and penetration testers doing reconnaissance on a target domain — run it in seconds from anywhere, no local toolchain needed
- SEO professionals mapping out a competitor's domain structure or auditing a client's subdomain footprint before a migration
- IT and DevOps teams who want a fast, readable inventory of what's actually live under their domain without digging through DNS records manually
- Developers and agencies who need to automate subdomain discovery as part of a larger pipeline via API or MCP
How to get started
- Click the link below and hit Try for Free on Apify
- Enter your domain or paste a list using Bulk Edit
- Hit Start
- Review results in the UI or export them
We also put together a short video walkthrough if you want to see it in action: Watch on YouTube
Questions or feature requests? Reach out — we're actively building on this.
Try the Real Subdomain Finder free on Apify
