Does HTTP/2 make websockets obsolete?

HTTP/2 and WebSockets are two distinct technologies that address different problems. Understanding their design and use cases helps answer this question.

HTTP/2's Key Features:

1. Binary Protocol: Unlike HTTP/1.x's text-based protocol, HTTP/2 uses binary format, enabling faster and more efficient parsing.
2. Multiplexing: Multiple requests and responses can be sent in parallel over a single connection without sequential ordering, significantly reducing latency.
3. Header Compression: HTTP/2 reduces header size through HPACK compression, lowering bandwidth consumption.
4. Server Push: Servers can proactively send resources to clients without explicit requests.

WebSockets' Key Features:

1. Full-Duplex Communication: Clients and servers can exchange data simultaneously, supporting bidirectional communication.
2. Persistent Connection: Once established, a WebSocket connection remains open until explicitly closed by either party.
3. Low Latency: WebSockets provide very low communication latency, ideal for applications requiring fast, real-time interaction.

Comparison and Use Cases:

While HTTP/2 offers improved performance features like multiplexing and server push, it can serve as a viable alternative in scenarios where only server-to-client one-way real-time push is needed. However, WebSockets provide true bidirectional communication and lower latency, which are essential for applications requiring complex, high-frequency bidirectional interactions, such as online gaming and real-time trading platforms.

Conclusion:

HTTP/2 is unlikely to obsolete WebSockets, as both technologies have overlapping capabilities but distinct strengths suited for different problems. HTTP/2 can replace HTTP/1.x in most applications optimizing latency and bandwidth, while WebSockets excel in applications demanding full-duplex and real-time communication.

For example, consider developing a stock trading platform requiring real-time stock price display and instant user trades. Using WebSockets for trade operations is appropriate due to the need for fast bidirectional communication. For real-time stock price updates, although HTTP/2 server push could work, the low latency and persistent connection of WebSockets are better suited for potential high-frequency updates and complex user interactions.