5 SecurityTrails Alternatives (DNS, WHOIS and Subdomain Lookups)

SecurityTrails is a freemium platform providing historical DNS, WHOIS and subdomain data for domains and IP addresses. Its historical archive is the main thing you're paying for beyond the free tier — the ability to look back at how a domain's records changed over time.

The alternatives below are mostly free, single-purpose tools rather than one platform that does everything: some map subdomains and hosts, one searches Certificate Transparency logs, one is a general free toolbox of DNS/WHOIS/reverse-IP lookups, one specializes in reverse-WHOIS by registrant name, and one is a broader internet-wide scanning platform. Deciding between them mostly comes down to whether you need current-state lookups (most of these are free) or the kind of historical record and account-based workflow SecurityTrails charges for.

Three of the five alternatives here are free with no account required (DNSDumpster, crt.sh and ViewDNS.info); Whoxy and Netlas are both freemium, like SecurityTrails itself.

Looking at the original? See SecurityTrails in the directory.

Alternatives

DNSDumpsterFreeFree domain research tool that maps a domain's subdomains and hosts.DNSDumpster is a free domain research tool that maps a domain's subdomains and hosts, covering the core subdomain-mapping use case of SecurityTrails at no cost.

crt.shFreeSearches Certificate Transparency logs to enumerate a domain's certificates and subdomains.crt.sh searches Certificate Transparency logs to enumerate a domain's certificates and subdomains, a free way to surface subdomains that SecurityTrails would otherwise show from its own index.

ViewDNS.infoFreeCollection of free DNS, WHOIS, reverse-IP and network lookup tools.ViewDNS.info is a free collection of DNS, WHOIS, reverse-IP and network lookup tools, giving a broader free toolbox to pair with the others.

WhoxyFreemiumWHOIS lookup and reverse-WHOIS history, including registrant-name search.Whoxy is freemium like SecurityTrails and specializes in WHOIS lookup and reverse-WHOIS history, including registrant-name search, which is a more targeted alternative if what you need is historical ownership records.

NetlasFreemiumInternet-wide scanning and attack-surface search platform.Netlas is a freemium internet-wide scanning and attack-surface search platform, a broader alternative if you want to search exposed infrastructure rather than just DNS and WHOIS records.

Browse the full tools directory →

Common questions

Do I need an account to use these SecurityTrails alternatives?

DNSDumpster, crt.sh and ViewDNS.info are free to use without an account. Whoxy and Netlas are freemium, so deeper lookups or higher volume may require a paid account, the same as SecurityTrails.

Which alternative is closest to SecurityTrails's historical DNS data?

None of the free tools listed here reproduce SecurityTrails's full historical archive on their own; Whoxy comes closest for historical WHOIS/registrant records specifically.

Is it legal to look up who owns a domain?

Laws vary by jurisdiction and consent matters, particularly around what you do with registrant information once you find it. See our guide on ethics and law for more.

Can I use these tools to check my own domain's exposure?

Yes — running your own domain through DNSDumpster, crt.sh or Netlas is a reasonable way to see what subdomains, certificates or exposed services are publicly discoverable about infrastructure you control.