DEV Community

Cover image for TCP vs. UDP: The Need for Speed vs. Reliable Delivery
Matheus Costa
Matheus Costa

Posted on

TCP vs. UDP: The Need for Speed vs. Reliable Delivery

When it comes to transmitting data over the internet, there are two main protocols: TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). Both protocols have their own advantages and disadvantages, and understanding these differences can help you choose the right one for your specific needs.

What is TCP?

TCP is a reliable protocol that provides error-free data transmission by establishing a connection between two devices before sending data. TCP sends data in small packets called segments, and each segment requires an acknowledgement from the receiving device before it can send the next segment. This ensures that data is delivered in the correct order and without errors. However, the overhead associated with establishing a connection and error checking can slow down data transmission speeds.

Some pros and cons of TCP include:

Pros: Reliable data transmission, error correction, ordered data delivery
Cons: Slower speeds due to connection establishment, higher overhead

What about UDP?

UDP, on the other hand, is a faster and more efficient protocol that does not establish a connection before sending data. Instead, it simply sends packets of data, or datagrams, to the recipient. UDP does not perform error checking or retransmission of lost packets, making it less reliable than TCP but faster for real-time applications such as gaming or video streaming.

Some pros and cons of UDP include:

Pros: Fast data transmission, low overhead, suitable for real-time applications
Cons: Unreliable data transmission, no error correction or recovery, unordered data delivery

So which protocol should you use? It depends on your specific use case. If you need reliable data transmission, such as for file transfers or email, then TCP is the way to go. If you prioritize speed over reliability, such as for online gaming or video streaming, then UDP may be a better choice.


TCP and UDP have their own pros and cons, and choosing the right protocol depends on your specific data transmission needs. Understanding the differences between these two protocols can help you make better decisions for your application.

Top comments (3)

pinotattari profile image
Riccardo Bernardini

It should also be said that it is a good idea to do some congestion control even when using UDP. See, for example

costamatheus97 profile image
Matheus Costa

Thanks for the suggestion

msoup profile image

I wish I could have seen examples of how to implement both in an app.