TCP vs. UDP: What’s the Difference Between Them?

When it comes to network protocols, TCP and UDP are two of the most commonly used protocols. This is because both protocols are used to transmit data over the internet, but they have some significant differences. In today’s article, we’ll explore TCP vs. UDP differences, including their strengths and weaknesses.

DNS using UDP and TCP

TCP: Transmission Control Protocol

TCP is a connection-oriented protocol that provides reliable data transmission. It establishes a virtual connection between the sender and receiver before transmitting data. As a result, TCP ensures that data is delivered in the correct order and without errors. This is achieved by assigning sequence numbers to each packet of data and acknowledging the receipt of each packet.

Strengths of TCP:

  • Reliable: TCP guarantees that all packets will be delivered without any errors.
  • Ordered: It ensures that packets are delivered in the same order they were sent.
  • Connection-oriented: TCP establishes a connection between the sender and receiver before transmitting data.

Weaknesses of TCP:

  • Slow: TCP is slower than UDP due to its connection-oriented nature.
  • Overhead: TCP has a higher overhead than UDP, which means it uses more network resources.

UDP: User Datagram Protocol

UDP is a connectionless protocol that provides unreliable data transmission. It does not establish a connection before transmitting data and does not guarantee that all packets will be delivered. UDP is often used for real-time applications such as video and audio streaming, where speed is more important than reliability.

Strengths of UDP:

  • Fast: UDP is faster than TCP due to its connectionless nature.
  • Low overhead: It has a lower overhead than TCP, which means it uses fewer network resources.

Weaknesses of UDP:

  • Unreliable: UDP does not guarantee that all packets will be delivered or that they will be delivered in the correct order.
  • No congestion control: UDP has no congestion control mechanisms, which means it can contribute to network congestion.

TCP vs. UDP: Which Should You Use?

Choosing between TCP vs. UDP depends on the specific application and its requirements. If reliability is important, TCP is the best choice. On the other hand, if speed is more crucial than reliability, UDP is the way to go. Applications such as video and audio streaming, online gaming, and VoIP typically use UDP. On the other hand, applications such as web browsing, email, and file transfers usually use TCP.


Comparing TCP vs. UDP shows that these two protocols serve completely different purposes. TCP is reliable but slow, while UDP is fast but unreliable. When choosing between the two, it’s important to consider the application’s requirements and select the best protocol.