NATS vs Socket.IO: What are the differences?
NATS: Lightweight publish-subscribe & distributed queueing messaging system. Unlike traditional enterprise messaging systems, NATS has an always-on dial tone that does whatever it takes to remain available. This forms a great base for building modern, reliable, and scalable cloud and distributed systems; Socket.IO: Realtime application framework (Node.JS server). Socket.IO enables real-time bidirectional event-based communication. It works on every platform, browser or device, focusing equally on reliability and speed.
NATS and Socket.IO can be primarily classified as "Realtime Backend / API" tools.
"Fastest pub-sub system out there" is the top reason why over 13 developers like NATS, while over 186 developers mention "Real-time" as the leading cause for choosing Socket.IO.
Socket.IO is an open source tool with 46.7K GitHub stars and 8.53K GitHub forks. Here's a link to Socket.IO's open source repository on GitHub.
PedidosYa, Trello, and triGo GmbH are some of the popular companies that use Socket.IO, whereas NATS is used by Apcera, Workiva, and Bridgevine. Socket.IO has a broader approval, being mentioned in 555 company stacks & 385 developers stacks; compared to NATS, which is listed in 27 company stacks and 11 developer stacks.