Subdomain Finder
Check 24 common subdomains using DNS-over-HTTPS. Find active subdomains for any domain — useful for SEO site structure analysis and security audits.
Subdomain Finder
Check 24 common subdomains using DNS-over-HTTPS. Find active subdomains for any domain — useful for security audits and SEO structure analysis.
Subdomain Scanner
Subdomain Security Considerations
Subdomains like admin., dashboard., or portal. should be protected with strong authentication, IP allowlists, or VPN access only.
Abandoned subdomains can be hijacked if the underlying service (e.g., a deleted GitHub Pages or Heroku app) is no longer active. Regularly audit and remove unused DNS records.
Ensure every active subdomain has a valid SSL certificate. A wildcard certificate (*.example.com) makes this easier to manage.
If a CNAME points to an unclaimed external service, attackers can register that service and take over your subdomain. Use CAA records and monitor DNS regularly.
Frequently Asked Questions
What is the Subdomain Finder?
The Subdomain Finder is a free online tool that check 24 common subdomains using dns-over-https. find active subdomains for any domain — useful for seo site structure analysis and security audits.. It runs entirely in your browser with no installation or sign-up needed.
How does subdomain discovery work?
This tool checks 24 common subdomain names (www, mail, api, blog, shop, admin, etc.) by looking up their DNS A and CNAME records using DNS-over-HTTPS via Cloudflare.
Is subdomain takeover a real risk?
Yes. If a CNAME record points to an unclaimed external service (like a deleted Heroku app or GitHub Pages), an attacker can register that service and take over your subdomain.
For more comprehensive scanning?
This tool checks 24 common subdomains. For full enumeration, use tools like Subfinder, Amass, or SecurityTrails which check thousands of subdomain patterns.
Is the Subdomain Finder free to use?
Yes, the Subdomain Finder is 100% free with no registration, no hidden fees, and no usage limits. All processing happens locally in your browser, ensuring complete privacy.
Is my data safe with this tool?
Absolutely. The Subdomain Finder processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.
Does the Subdomain Finder work on mobile devices?
Yes, the Subdomain Finder is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.
Do I need to create an account to use this tool?
No account or registration is needed. Simply open the Subdomain Finder in your browser and start using it immediately. There are no sign-up walls or usage restrictions.
How do I use the Subdomain Finder?
Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.
Which browsers are supported?
The Subdomain Finder works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.
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About Subdomain Finder
Subdomain Finder is a free, browser-based tool in our Domain Tools collection. Everything runs locally on your device — no uploads, no sign-up, and your data stays private.