Beginner’s guide to OSINT
Practical, plain-language guides to open-source intelligence: what it is, how to investigate domains, IPs, usernames and emails, and how to stay within legal and ethical limits.
All topics
What is OSINT?OSINT is intelligence built from public sources. Learn what it is, what it is for and where its limits are.Domains and DNSHow to investigate a domain: WHOIS/RDAP, DNS records, subdomains and certificate transparency.IP addresses and networksWhat an IP address can and cannot tell you: geolocation, ASN, reverse DNS and exposed services.Usernames and email addressesPivoting from a username or email using public profiles, without crossing the line into harassment.Method and responsible useA simple OSINT workflow: question, collection, verification, documentation, and the legal and ethical limits.Use public sources only, for lawful purposes. Verify every finding independently.