Domain, IP & DNS Research

Google Transparency Report

transparencyreport.google.com

Google certificate transparency search for checking certificates and HTTPS records.

photon

pypi.org

Python OSINT crawler for extracting URLs, files, endpoints, and related website data.

Domain intelligence tool for researching WHOIS data, ownership patterns, and connected domains.

Whoxy

whoxy.com

Whoxy is a hosted web service that returns parsed WHOIS fields to applications in XML or JSON format over HTTP requests. It follows WHOIS registry referral chains to find the correct servers, and supports 2026 domain extensions including gTLDs and ccTLDs. The page notes a free account signup and query pricing by volume.

metabigor

github.com

OSINT tool for collecting domain, IP, ASN, and infrastructure intelligence from multiple sources.

Domain monitoring tool for tracking DNS changes, records, and domain activity.

FOFA

fofa.so

Internet asset search engine for discovering exposed services, hosts, domains, and technologies.

Internetdb.shodan.io

internetdb.shodan.io

Shodan InternetDB lookup for checking open ports, vulnerabilities, tags, and host data by IP.

LeakIX

leakix.net

LeakIX is a search and reporting platform with query syntax for ports, protocols, ASNs and IP ranges. It offers free and commercial plans, with paid tiers providing faster access to results, higher request limits, critical and RCE plugins, alert channels and downloadable results. Sponsorship supports voluntary researchers who dispatch free reports to companies and institutions.

Netlas.io

netlas.io

Internet asset search engine for domains, IPs, ports, certificates, and exposed services.

ONYPHE

onyphe.io

OSINT search engine for exposed assets, IPs, domains, certificates, and network data.

Web vulnerability search engine for finding reported security issues across websites.

SecurityTrails

securitytrails.com

Attack-surface and DNS intelligence platform for domains, subdomains, IPs, and historical records.

Internet asset intelligence platform for domains, IPs, certificates, and exposed infrastructure.

Cyberspace search engine for finding internet-connected assets, devices, and exposed services.

Internet Census 2012 is a research paper describing a distributed port scanner built on insecure embedded devices with empty or default credentials. It scanned all IPv4 addresses and includes service probes for common ports, ICMP ping, reverse DNS and SYN scans. Data gathered during the research was released into the public domain.

OSINT.sh tool for checking historical WHOIS records and domain ownership changes.

Alexa

alexa.com

Website information page for traffic estimates, site metadata, and audience insights.

Internet asset search engine for domains, hosts, certificates, and exposed services.

IP intelligence tool for checking scan traffic, noisy hosts, and suspicious internet activity.

Wappalyzer

wappalyzer.com

Wappalyzer is a website technology checker that identifies the technologies a site is built with, including CMS and ecommerce platforms, analytics tools, frameworks and infrastructure services. It supports single-domain lookups or bulk analysis of thousands of sites, and can also be used in the browser, in a CRM, or through an API.

Free online network tools

centralops.net

CentralOps collection of DNS, WHOIS, traceroute, email, and network lookup tools.

OSINT Toolkit Website Information is a collection of tools for researching websites, IP addresses, domains, emails and MAC addresses. It lists lookups including Ping Website, Whois, reverse Whois, network and TLD lookup, IP history and geolocation, MAC vendor lookup, DNS report and header and source code search. The page states that some tools require the IP address, email address, domain name or MAC address of the target.

IANA — Root Zone Database

iana.org

IANA database listing top-level domains, registry operators, and root zone delegation data.