How do you choose between WebSockets and HTTP/2 for real-time communication?

2 What is HTTP/2?

HTTP/2 is a major revision of the HTTP protocol that aims to improve the performance, efficiency, and security of web applications. HTTP/2 introduces several enhancements over HTTP/1.1, such as multiplexing, header compression, server push, and stream prioritization. HTTP/2 is still based on the request-response model, but it allows multiple concurrent requests and responses to be sent over a single TCP connection, reducing the overhead and latency of HTTP/1.1.

4 What are the pros and cons of WebSockets?

WebSockets offer several advantages compared to HTTP/2, such as enabling bidirectional and full-duplex communication, as well as reducing the overhead and bandwidth of HTTP headers. Additionally, they support custom protocols and subprotocols that can be tailored to application needs. However, there are a few drawbacks, such as incompatibility with some proxies, firewalls, and antivirus software. They are also more vulnerable to cross-site WebSocket hijacking (CSWSH) attacks and more complex to implement and debug, as they require a dedicated server and client library.

5 What are the pros and cons of HTTP/2?

HTTP/2 has some advantages and disadvantages compared to WebSockets. The pros include compatibility with most existing web infrastructure, as well as increased security and robustness due to TLS encryption, stream error handling, and flow control. It is also more flexible and scalable, as it supports multiplexing, server push, and stream prioritization. On the other hand, it is limited by the request-response model which may not be suitable for some real-time scenarios that require unsolicited data from the server or the client. Additionally, it is affected by the head-of-line blocking problem which can cause delays or timeouts if one stream is blocked by another. Moreover, it is more difficult to inspect and monitor due to its binary framing layer that is not human-readable.

6 How do you choose?

When deciding which protocol is best for real-time communication, there is no one-size-fits-all answer as it depends on various factors such as application requirements, network conditions, browser support, and the developer’s preference. Generally speaking, WebSockets should be used if bidirectional and full-duplex communication, low latency, and high throughput are desired. On the other hand, HTTP/2 is advantageous for compatibility, security, efficiency, or flexibility for general web browsing or RESTful APIs. A hybrid approach may be best if both WebSockets and HTTP/2 features are desired or to leverage the best of both worlds.