The protocols that allow communication between the client and the server are essential for browsing the web. HTTP has existed for more than 30 years, but changes have been made so that the protocol remains high-performing. In this article we will in particular take an interest in the latest version, which is coming soon.
A few words about HTTP
HTTP is the acronym for HyperText Transfer Protocol, created by Tim Berners-Lee in 1989 for use on the World Wide Web (WWW). The objective with HTTP is to enable communication between the client and the server in a fast, smooth and secure way.
Indeed, when you carry out a search in your browser, an HTTP request is sent to the web server. This makes it possible to retrieve the files needed to display the requested website.
The protocol was adopted by browsers with the aim of standardising the rules of communication between the client and the server. HTTP 1.1, as it was known, served for more than 15 years before being improved into HTTP 2.
The move to HTTP 2
The second major update to HTTP was made in 2014. It made it possible to improve both the security and the speed of communications. Indeed, websites have become increasingly dynamic, with different file, image and video formats.
Previously, a request that was sent retrieved only a single file, so HTTP 1 needed several requests to display a website. HTTP 2 improves speed in this respect because it needs only a single request to ask for all the files needed to load the site.
What will HTTP 3 bring?
HTTP 3 is the latest major update to the protocol that is expected. It is already supported in Edge, Firefox and Safari. It is an improvement on HTTP 2 whose objective is to bring even more speed. Nevertheless, one big change is expected: the replacement of TCP by UDP.
TCP vs UDP
The TCP protocol has existed for more than 40 years; it is much appreciated for the security it guarantees during data transmission thanks to TLS (Transport Layer Security). Indeed, the protocol sends a confirmation to the sender that the data sent has been received correctly (ACK, acknowledgement). However, TCP can cause slowdowns when a data packet is lost because, without the ACK, it automatically stops the transmission of the other packets until that one is found.
QUIC UDP Internet Connections is the acronym associated with the User Datagram Protocol developed by Google; it overcomes TCP’s problem because it does not need to wait for the transmission of one packet to succeed before sending the other packets.
The advantages of HTTP 3
HTTP 3 brings its share of advantages, among which we can highlight the speed of data transmission, loading speed and a stable, secure connection.
Data transmission
As explained above, data transmission with HTTP 3 can be done more quickly because using the UDP protocol does not block when a packet is lost. It is thus possible to save time during data transfer.
A fast and secure connection
The secure connection with HTTP 3 is made via zero round trip, better known as 0-RTT. This makes it possible to establish connections much more quickly, since 0-RTT does not take the TLS ACK into account.
However, in order to establish a risk-free connection with 0-RTT, Google’s team had to develop an additional layer of security, added to the protocol. It is therefore possible to establish a secure communication with a single transmission.
Loading speed
Data transmission that is not blocked makes it possible to start loading a website sooner. The connection, established almost instantly, makes it possible to obtain the data in less time. All of this improves the loading speed of websites. This is especially valuable for loading sites on mobile networks (3G, 4G).
A little more patience will be needed before HTTP 3 is used by all web browsers, because the protocol is in the process of being standardised. The American company Cloudflare is actively taking part in this and supports the preliminary version.
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