Use HTTP/2 for all Resources

Compared to HTTP/1.1, the HTTP/2 protocol provides web developers with more control over how elements, such as CSS, JavaScript, images, etc., are prioritized during the page load process. We discussed how these render-blocking resources affect the immediate page load process. If these elements block the page from rendering, it may appear to the user that something is wrong with your site, or not loading at all. HTTP/2 includes support for multiplexing, which allows the server to send multiple data streams at once instead of one at a time. Developers can set a priority, or weighted value, so that when a user requests a web page, the elements or content that you want them to see first, second, third, etc., can be set. Another benefit to HTTP/2 is the ability to utilize HPACK compression for HTTP messages, which can remove duplicate information from messages and make them smaller, saving data and speeding up load page times.

As of July 2021, the HTTP/3 protocol was officially drafted. This protocol uses a new transport protocol, QUIC (Quick UDP (User Datagram Protocol) Internet Connections), which is supposed to eventually replace the TCP and TLS (Transport Layer Security) protocols. HTTP/3 offers benefits like faster data transfer rates, better reliability, and increased security/encryption features versus HTTP/2. However, at this time, QUIC has only seen limited adoption rates.