What is HTTP / 2

What is HTTP / 2

HTTP / 2 is a communication method required to retrieve web page data from a server, and was released in 2015. Compared to HTTP / 1.1 published in 1999, web pages can now be loaded more efficiently, and the loading speed has also improved significantly.This time, I will explain in detail the history of HTTP, the mechanism of HTTP / 2, and the merits of using HTTP / 2.“HTTP” is a protocol, or convention, for communicating between a client and a server on the Web. The format and procedure for data transmission are fixed.Four specifications of “HTTP” have been released while undergoing a transition from “HTTP / 0.9”, which was born in 1991, to “HTTP / 2 (HTTP / 2.0)” in 2015. Below, let’s introduce four HTTPs in order of appearance.

HTTP / 0.9 was released in 1991

The first version of HTTP, “HTTP / 0.9”, was published in 1991. Originally called “HTTP”, it was later named “HTTP / 0.9” to distinguish it when later versions such as “HTTP / 1.0” appeared.It has only a simple structure, and the GET method can only get pages from the server and disconnect. Also, only HTML files can be transferred, not images.

HTTP / 1.0 was released in 1996

What is HTTP / 2, In “HTTP / 1.0” released in 1996, a header was added to the send / receive format, and it became possible to send by methods such as DELETE, PUT, and POST in addition to GET. Therefore, additional image files can be sent and received.In addition, a version has been added to the request header to distinguish it from the “HTTP / 0.9” mentioned above.

HTTP / 1.1 was released in 1999

What is HTTP / 2, In “HTTP / 1.1”, a function called “pipe lining” that can transfer the next request before the transfer is completed has been added to speed up communication. At the same time, by enabling “Keep-Alive” by default, the communication speed is increased by the function to refer to the previous connection when reconnecting.We also supported a technology called “TLS” that enhances communication security. TLS is a mechanism that was born by reviewing the design in order to solve the vulnerability of the encryption technology “SSL” that had existed before that. Currently, this TLS is referred to as “SSL” or “SSL / TLS”.By using this “TLS (SSL)”, it is possible to upgrade from HTTP to WebSocket (two-way communication protocol), HTTPS, and HTTP / 2.

HTTP / 2 was released in 2015

What is HTTP / 2, “HTTP / 2 (HTTP / 2.0)” released in 2015 aims to eliminate the delay in display speed due to the complicated content structure of Web pages. By creating virtual TCP sockets called “streams” and processing them in parallel, the speed of data transmission and reception is increased.At the same time, high-speed communication is enabled by a technology called “server push” that predicts content such as JavaScript, CSS, and image data and sends it before request, and data transmission / reception in frame units using a binary-based protocol.

What is HTTP / 2?

“HTTP / 2 (HTTP / 2.0)” is compatible with the previous version “HTTP / 1.1”, and the default port number used is 80 for http and 443 for https.Currently, many web browsers support HTTP / 2, but only the identifier “h2” that uses the encryption technology “TLS” is supported, and “HTTPS” encrypted communication is required.

Differences between HTTP / 2 and HTTP / 1

Up to “HTTP / 1.1”, you could only send one request to the web server one by one, and you couldn’t fulfill the next request until the previous request was completed. For example, after loading the first image of a web page, load the next image, and so on.On the other hand, “HTTP / 2”, which can process in parallel, can send multiple requests to the Web server at the same time. Since two or more images can be loaded at the same time, the loading speed of the entire web page will be faster.

Advantages of using a rental server that supports HTTP / 2

What is HTTP / 2, Supporting “HTTP / 2” speeds up and streamlines communication between the client and server, which can increase the transmission speed of the content itself. It will enable efficient requests that predict the page display in the web browser, so the time until the web page is displayed will be shortened.In particular, Web pages with more content such as images and videos can take advantage of HTTP / 2.

What to do to adapt HTTP / 2 on your rental server

Even if the rental server you use supports HTTP / 2, you cannot use it unless the web page is compatible with HTTP / 2. What can I do to make an existing page available for HTTP / 2 communication?

Make the site SSL

What is HTTP / 2, By making the website SSL, HTTP / 2 communication can be used when using the browser of Google Chrome or Firefox. In addition, SSL-enabled sites are a high-ranking factor in ranking Google search results with many users, and prevent attacks from malicious third parties such as site spoofing and leakage of personal information. You can do it.To take full advantage of HTTP / 2 on your rental server, you need to use “TLS” to encrypt your website to “HTTPS”. Ask the server to issue an “SSL certificate”, and when the process is complete, change the beginning of the URL of the web page from “http: //” to “https: //” to display the page.If you follow the internal links and display images without any problems, the encryption of the web page is complete.

How to check if you are communicating via HTTP / 2

What is HTTP / 2, To check if the communication with the server is done by “HTTP / 2 (HTTP / 2.0)”, use the method of installing the plug-in in Firefox or Google Chrome, or use the site that can be checked by just entering the URL. There is a way to do it.keycdn | HTTP / 2 Test https://tools.keycdn.com/http2-testIf you can support HTTP / 2, enter the URL of the web page you want to check in the search window and execute it, and “Yeah! (Entered URL) supports HTTP 2.0.” Will be displayed at the bottom.

Speed ​​up your site with an HTTP / 2-enabled rental server

What is HTTP / 2, it can improve the display speed of Web pages compared to the previous HTTP / 1.1.