Engine.IO is the underlying transport engine for Socket.IO, handling low-level connections between client and server. It manages various transport protocols like WebSocket, HTTP long-polling, and FlashSockets, automatically selecting the best available option for reliability and speed. Engine.IO abstracts away transport complexities, providing a consistent interface for Socket.IO to build real-time communication features. It focuses on robust connection management, reconnection strategies, and handling network disruptions, ensuring a stable bidirectional communication channel.
Engine.io's release frequency is sporadic. There were bursts of releases in 2012-2014, with peaks in October 2012 and August 2013. Release activity decreased significantly after 2017, with many months having no releases. 2024 saw a slight resurgence, but 2025 has been quiet so far.
Engine.io downloads show a generally upward trend from March 2024 to August 2025, ranging from 16.4 million to 37.1 million. September 2025 downloads are significantly lower at 8.9 million, but represent only a partial month. Overall, engine.io exhibits strong and growing usage.
