Online DNS & Subdomain Recon Tools

Collection of web-based / online DNS tools useful during the reconnaissance phase of penetration testing and security assessments.

These tools focus on:

They complement CLI-based recon tools (see pentest-arsenal.md) and are ideal for quick, passive OSINT without local installation.

Core DNS Lookup & Investigation Tools

Name	Vendor/Webpage	GitHub Repo	Brief Description	Tags	Latest Commit	Creation Date	Stars
ViewDNS	viewdns.info	—	Multi-tool suite offering DNS, WHOIS, reverse IP, propagation, traceroute and more.	[dns, recon, lookup, propagation, osint]	—	~2008	—
DNSLookup	dnslookup.org	—	Advanced DNS lookup tool with detailed record parsing and visualization.	[dns, lookup, records, analysis]	—	~2015	—
DNSlytics	dnslytics.com	—	Online DNS and IP investigation platform with historical data and maps.	[dns, investigation, intel, osint]	—	~2016	—
DNS Spy	dnsspy.io	—	Monitors DNS configurations, detects changes, and validates settings.	[dns, monitor, validation, config]	—	~2017	—
Zonemaster	zonemaster.iis.se	—	Advanced DNS zone testing tool to verify configuration and best practices.	[dns, tester, zone, validation]	—	~2013	—
Leaf DNS	leafdns.com	—	Comprehensive DNS health and delegation tester.	[dns, tester, health, delegation]	—	~2010	—
intoDNS	intodns.com	—	Checks DNS and mail server health, misconfigurations, and common issues.	[dns, health, checker, mail]	—	~2009	—

Subdomain Enumeration & DNS Recon

Name	Vendor/Webpage	GitHub Repo	Brief Description	Tags	Latest Commit	Creation Date	Stars
Find Subdomains Online	findsubdomains.com	—	Web interface to discover subdomains for security assessments and pentests.	[subdomain, enum, recon, osint]	—	~2018	—
DNSdumpster	dnsdumpster.com	—	Free DNS recon & research tool; maps hosts, subdomains, and records.	[dns, recon, subdomain, dump]	—	~2014	—
DNS Table	dnstable.com	—	Searches public DNS records by domain, IP, CIDR block, or ISP.	[dns, search, records, database]	—	~2015	—

DNS Propagation & Delegation Checkers

Name	Vendor/Webpage	GitHub Repo	Brief Description	Tags	Latest Commit	Creation Date	Stars
What's My DNS	whatsmydns.net	—	Popular global DNS propagation checker from hundreds of locations worldwide.	[propagation, checker, dns, global]	—	~2012	—
dnslookup (ceipam)	ceipam.eu/en/dnslookup.php	—	Excellent DNS propagation checker with detailed global views and extras.	[propagation, checker, dns, global]	—	~2015	—
BuddyDNS Delegation LAB	buddyns.com/delegation-lab	—	Visualizes, traces, and validates domain name delegation paths.	[dns, delegation, trace, visualize]	—	~2012	—
DNS Bajaj	zonecut.net/dns	—	Simple delegation checker showing authoritative name servers.	[dns, delegation, checker]	—	~2005	—
DNSSEC Debugger	dnssec-debugger.verisignlabs.com	—	Validates DNSSEC chain, DS, and DNSKEY records.	[dnssec, validation, debugger]	—	~2010	—

Historical & Wildcard DNS Services

Name	Vendor/Webpage	GitHub Repo	Brief Description	Tags	Latest Commit	Creation Date	Stars
PTRarchive	ptrarchive.com	—	Archives and searches historical reverse DNS (PTR) records.	[ptr, historical, reverse, archive]	—	~2010	—
xip.io	xip.io	—	Free wildcard DNS service resolving to any IP (great for local/dev testing).	[wildcard, dns, testing, local]	—	2011	—
nip.io	nip.io	—	Dead-simple wildcard DNS for any IP address (modern xip.io alternative).	[wildcard, dns, testing, local]	—	~2014	—

Advanced / Specialized DNS Tools

Name	Vendor/Webpage	GitHub Repo	Brief Description	Tags	Latest Commit	Creation Date	Stars
DNSGrep	blog.erbbysam.com/.../dnsgrep	—	Command-line style search across large public DNS datasets (web interface).	[dns, search, grep, datasets]	—	2019	—