Protocol Explorer is a free, interactive network simulator that shows how the internet really works, packet by packet. You watch HTTP, HTTPS, TCP, TLS, DNS and other protocols in motion, with every packet decoded byte by byte. Animated lessons - available in 8 languages - walk through DNS lookups, TCP handshakes and TLS encryption step by step. It is built for students, developers and anyone learning networking who wants to see protocols behave in real time instead of memorizing static diagrams. It runs entirely in the browser. HTTP and HTTPS lessons are free, and a one-time $5 payment unlocks all 39 lessons.
Networking is usually taught through static diagrams that freeze protocols at a single moment, which makes concepts like handshakes and encryption feel abstract and hard to internalize. Protocol Explorer was built to fix that: instead of reading about how packets move, you watch a DNS query resolve or a TLS session get negotiated, byte by byte, and the protocol finally makes sense.