HTTP 1.1 vs HTTP 2

The Hypertext Transfer Protocol, or HTTP, is an application protocol that has been the de facto standard for communication on the World Wide Web since its invention in 1989. From the release of HTTP/1.1 in 1997 until recently, there have been few revisions to the protocol.

HTTP/1.1

Developed by Timothy Berners Lee in 1989 as a communication standard for the World Wide Web. In this process, a client sends a text-based request to a server by calling a method like GET or POST. In response, the server sends a resource like an HTML page back to the client. For example, let’s say you are visiting a website at the domain www.example.com. When you navigate to this URL, the web browser on your computer sends an HTTP request in the form of a text-based message.

GET /index.html HTTP/1.1
Host: www.example.com

This request uses the GET method, which asks for data from the host server listed after Host:. In response to this request, the example.com web server returns an HTML page to the requesting client, in addition to any images, style-sheets, or other resources called for in the HTML.

OSI layers

HTTP/2

HTTP/2 published in May 2015, began as the SPDY protocol (SPDY pronounced “speedy” is a deprecated open-specification networking protocol that was developed for transporting web content. SPDY manipulates HTTP traffic, with particular goals of reducing web page load latency and improving web security), developed primarily at Google with the intention of reducing web page load latency by using techniques such as compression, multiplexing, and prioritization. From the beginning, many browsers supported this standardization effort, including Chrome, Opera, Internet Explorer, and Safari. Due in part to this browser support, there has been a significant adoption rate of the protocol since 2015, with especially high rates among new sites.

From a technical point of view, one of the most significant features that distinguishes HTTP/1.1 and HTTP/2 is the binary framing layer, which can be thought of as a part of the application layer in the internet protocol stack.HTTP/2 uses the binary framing layer to encapsulate all messages in binary format where HTTP/1.1, which keeps all requests and responses in plain text format.

HTTP/1.1 vs HTTP/2

Conclusion

As you can see, HTTP/2 differs from HTTP/1.1 in many ways, with some features providing greater levels of control that can be used to better optimize web application performance and other features simply improving upon the previous protocol.