PassiveDNS

SecurityTrails is a tool for domain intelligence and security. It helps you find risks, track domain changes, and understand your online footprint, useful for IT security folks and businesses.

dnshistory.org is a cool site that lets you dig into DNS history. It's perfect for curious netizens or web pros wanting to track domain - related changes over time.

This is the PTR Archive site. It's a cool place for tracking historical PTR records. Useful for those researching DNS history, it offers a neat way to dig into old network data.

DNSdumpster is a nifty tool for domain research. It lets you dig into DNS records, discover sub - domains, and view network maps. Great for security analysts and web researchers.