The two aren't necessarily the same kind of thing. WebSocket-Node is a low-level WebSocket framework. It supports both text and raw binary WebSocket messages.

The two aren't necessarily the same kind of thing. WebSocket-Node is a low-level WebSocket framework. It supports both text and raw binary WebSocket messages. Socket.IO is not a WebSocket library, but sits one level higher on the stack. It's an abstraction layer that supports many different transports and overlays its own messaging semantics. For example, WebSocket-Node could theoretically provide the WebSocket transport for Socket.IO. If you want WebSocket specifically, and don't care about falling back to long-polling techniques, or you want something that allows you to use true binary messages, look at a WebSocket library rather than an abstracted communications library like Socket.IO.