What is the QUIC protocol, how it works and why it will be used in HTTP / 3

What is the QUIC protocol

QUIC is a network protocol created by Google. Its full name is Quick UDP Internet Connections, which if we translate it into Spanish we can say Fast UDP connections on the Internet. It is used to send packets over UDP. It was born as an alternative to TCP, which is the protocol that has been indispensable for Internet connections for decades.

Acts similar to HTTP / 2 and TLS / SSL, but instead of using TCP is based on UDP. They began to implement it in 2012, but it was in 2013 when they really did tests in Google Chrome to verify its operation and thus see the advantages it really has.

Today QUIC is already implemented as standard in the google browser. In others we can enable it, as is the case with Opera. It is hoped that soon more programs will use it. At the moment it is already running on different platforms of the search giant, such as YouTube, Gmail or Drive.

What is QUIC for

So what is the actual function of QUIC? We can say that it is a protocol that will be used to establish connections between the sender and the receiver. When you enter a page, in order to access the content, a series of data is sent. This includes certificates and exchange keys.

This type of protocol is necessary to navigate, play on the Internet, use video calling applications … It serves to offer a protection to that connection, something that we can also have with TLS / SSL, but in this case improved. It will offer better performance by decreasing latency.

What it basically does is transport packets on the network. But it has an important difference when it is based on UDP, and that is that the server that sends the information does not have to be in constant communication with the server that receives it. This is what remarkably helps decrease latency. You do not need time to check if that information has arrived correctly.

QUIC protocol on the Internet

Advantages of using QUIC in HTTP / 3

After explaining what the QUIC protocol created by Google is and what it is for, let’s see what its main advantages. These points will help us navigate the Internet faster and maintain security at all times. They are two important factors and that, thanks to more recent protocols like this one, have improved. HTTP / 3 and QUIC represent an important advance for what will be the Internet and its applications.


One of the advantages is the higher speed. This will allow loading a website in less time or using different applications. The HTTPS protocol has a negative point to consider, and that is that it uses TLS for the exchange or handshake. QUIC makes this faster.

This exchange is necessary to establish the TLS encryption and exchange the keys. Shorten the steps necessary to reach the same goal. In this case it starts the connection with a single packet or two if it is the first time.

Less hassle when switching networks

Something important that also improves the QUIC protocol is the stability when we change the network. When does this happen? If you are connected to a server with mobile data on a 4G or 5G network and you suddenly switch to Wi-Fi over TCP, it is going to cut out and you will have to reset again.

On the other hand, thanks to QUIC this network change is much more fluid and avoids problems. You will simply have to send a packet to establish the connection and not have to re-establish it again. This is very useful if, for example, we are sharing a data network on a computer and at any given moment we are interested in connecting to the Wi-Fi network.

Doesn’t affect packet loss as much

In the event that there is a loss of packets in HTTP / 2 over TCP, this can cause a significant performance problem. When a package is lost, the recipient must wait for it to be recovered.

What the QUIC protocol does to solve this is that it allows data streams to reach the recipient independently. There is no need to wait for those lost data packets to be recovered, and therefore it is not as much of a concern if this happens.


One of the most important factors for the implementation of QUIC is the security. In this sense, Google developers have corrected one of the most important TCP flaws, which is the fact that the header of the sent packets is in plain text and can be read without authentication.

This that we mentioned could lead to a Man in the Middle attack, which basically consists of intercepting what is sent. But the QUIC protocol improves this and the packets that are sent are always encrypted and authentication by the recipient is required.

Allows multiplexed connections

The multiplexed connections They are those that use two or more signals and combine them to transmit through a single medium. This will allow multiple communications at the same time. This will streamline web application connections.

It must be taken into account that HTTP / 2 multiplexes the information through a single TCP flow and this means that, in the event that a TCP segment is lost, there is a blockage. QUIC improves this point and will allow multiplexed connections. HTTP / 3 will be able to send different multiplexed files through QUIC.

In short, the QUIC protocol comes to improve certain aspects and optimize Internet browsing. It is something that will be more and more present and that some browsers already use. Little by little we will see more applications and websites that use it. We can summarize that this protocol comes to improve the performance of any connection that uses TCP.

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