Domain Digger looks up DNS, WHOIS, IP data, SSL history, and subdomains for a domain.
SD Finder
Scan a domain for subdomains with Subdomain Finder, which offers private scans that are not logged or indexed.
About SD Finder
SD Finder is a web-based subdomain scanner hosted on C99.nl. It scans a given domain to enumerate as many subdomains as possible, which can help map a domain's structure, locate services hosted on subdomains, and spot subdomains that may be more exposed than others. A scan can take up to about one minute, and results for a scanned subdomain are stored in the service's cache for 7 days. The tool also checks whether a subdomain is tunneling through CloudFlare and can surface historical subdomains that are no longer linked to any endpoints. The directory description states that scans are private and are not logged or indexed, though results are cached by the service for the period noted above.
Key features
- Scans an entire domain to find as many subdomains as possible
- Reports whether a subdomain is tunneling through CloudFlare
- Finds historical subdomains no longer linked to endpoints
- Stores scanned subdomain data in a cache for 7 days
- Scan run from a browser; results shown on the page
- Donations accepted via PayPal or cryptocurrency
Best for: Security researchers and bug bounty hunters who want a quick overview of a domain's subdomains before investigating further.
Good for
- Combines subdomain enumeration with CloudFlare tunneling checks and historical subdomain discovery
- Frame-oriented output supports bug bounty target research
- Funded by optional donations via PayPal or cryptocurrency
Watch out for
- A scan may take up to about one minute
- No pricing or plan information is stated on the homepage
SD Finder at a glance
- Website
- subdomainfinder.c99.nl
- Category
- Development › Domain, IP & DNS Lookup
- Type
- Online tool
- Pricing
- Not confirmed. Check the site
- Platforms
- Web
- Open source
- Not stated
- Last checked
- Oct 6, 2026 · Online when checked
- Listed
- Oct 5, 2026
SD Finder alternatives
Tools and sites you could use instead, ranked by how closely they match.
Find subdomains and certificates linked to a website with Merklemap search and enumeration tools.
Whoxy provides a WHOIS API for looking up domain registration records from a database of historical records.
Paid
24 alternatives
IWantMyName registers domain names across more than 500 extensions and offers related plugins.
Domainr searches domain names and provides an API covering top-level domains.
Look up domain, IP, autonomous system, and entity records with RDAP.org RDAP-based lookup tool.
Popular in Domain, IP & DNS Lookup
Well-known listings from the same topic.
Cloudflare DNScloudflare.com/application-services/products/dnsGoogle Transparency Reporttransparencyreport.google.com/https/certificatesNetlas:netlas.ioIPIP.NETwhois.ipip.netInstantDomaininstantdomainsearch.com
SD Finder FAQ
How long does a scan take?
A scan can take up to about one minute, and the page asks users to wait while scanning completes.
How long are results kept?
After a subdomain has been scanned, the data is stored in the service's cache for 7 days.
Are scans private?
The directory description says scans are private and not logged or indexed; note that scanned subdomain data is still cached by the service for 7 days.
Is something wrong or out of date?
Tell us and an editor will check it.
Own this website?
Claim this listing
Claim the listing and suggest updates yourself. An editor checks every claim first.