Omegle - Omegle is one of the most popular online chat website allowing user to communicate with anyone without registration.
Ring4 Meeting - Dead simple video conferencing - free, in browser
Chatrandom - Chatrandom provides medium to users for having chat at random with different users around the globe.
Stork.ai - AI-Based Collaboration for Hybrid Teams. Rich media messaging, advanced video and voice conferencing, auto-transcribing and screen sharing. Serendipitous meetings at the water-cooler with your human and AI teammates.
LuckyCrush - Live random video chat
openmeet - Account free video conferencing with a rooms component that lets you use VC within a physical meeting room. The server can also be hosted in your own cloud for extra privacy/security.