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RJ45 vs RJ11: Know the Difference & Function in 2023?

Today In this Comparison, we compare RJ45 vs RJ11 to help you to choose a fast and reliable Cable.

Cables and connectors have always been an integral part of network communication. With the advancement made in technology, the demand for private networks and required devices has increased.

Speaking of cables and connectors, RJ45 and RJ11 connectors have been around for a long time. For those unversed, RJ stands for Registered Jack. It serves as an interface for data networks and telecommunication.

While RJ11 is widely used in analog telephony, RJ45 connectors are needed for both data and telecom networks. Just so you know the numbers 45 and 11 are the interface standards.

In this guide, we will highlight the main differences between the RJ45 vs RJ11. This will help you determine which connector to use and when.

RJ45 vs RJ11

The Function of RJ45

RJ45 is a compact, self-securing, and modular technology that is used to connect Ethernet cables to various electronic devices. It comes with eight pins and is connected to Ethernet interfaces.

Individual wires are installed in 8 places with a gap of 1mm between each plug. This is done with the help of special cable crimping tools. This type of connection is known as 8P8C (eight positions, eight contacts) connector.

RJ45 is slightly bigger than other connectors and can support up to 10 Gbps bandwidth using Ethernet cables. The good thing is that it can be extended further using a fiber media converter and fiber cable.

Another important thing to know about RJ45 connectors is that they work commonly with Cat6 and Cat5 cables. The advantage of using this type of connector is that it can be connected to various devices in a copper cable network. For example, you can connect it to computers, cables, switches, routers, and others.

Compared to other connectors RJ45 connectors are more flexible. Plus, they are backward compatible and can be used with analog telephony devices as well. These types of connectors have a rectangular shape, so they can accommodate more wires.

The Function of RJ11

RJ11 connector is used to connect traditional PSTN telephone networks. Instead of 8 pins, it has only 4 pins. Out of the 6 available connections, it uses the 2 center connections for wiring in a single telephone line. It is considered the standard connector for connecting a handset to the phone and the phone to the wall.

For the RJ11 interface, you need a 6P2C connection. However, you can also use 6P4C connectors in RJ11 cables. While the other two conductors remain unengaged, the two potential contact location link ring and tip.

RJ11 supports up to 24 Mbps bandwidth, which is much lesser than the RJ45 connector. Instead of Cat6 and Cat5 cables, RJ11 works with simple telephone cables.

It also has a different shape than RJ45 connectors. It has a square shape, which is more compact and small.

When to Use RJ45?

RJ45 is a type of connector that is mainly used for Ethernet networking. It has a similar design to a phone jack but is a little bigger. Ethernet cables have RJ45 connectors on each end, and they are known as RJ45 cables. It is the most popular type of cable in the IT industry.

An RJ45 connector can be used to connect various devices over an Ethernet network. Devices like printers, PCs, DSL modems, cable modems, or network storage devices use an RJ45 connection.

There exists different types of RJ45 connector: male connectors and female connectors. Sockets or jacks are females and plugs are males. The two are designed to fit together to provide a strong connection: both electrical and physical.

When to Use RJ11?

RJ11 is mainly used in telephone lines. Since it has 6 positions, it can accommodate up to 3 telephone lines. You can use this type of connector to connect a handset to the phone and phone with the wall socket.

RJ11 connectors can be of two types: RJ11C, which is used in table-top phones, and RJ11W, which is ideal for wall phones.

Although RJ11 is best suited for telephone lines or voice lines, you can also use it with older modems and fax machines. Many RJ11 connections are being replaced by RJ45 in today’s times.

Pros & Cons of RJ45


  • Low cost
  • Solderless assembly of wiring and connector
  • Easy insertion and removal
  • Allows customization of cables on-site
  • Provides better current protection


  • Limited flexibility

Pros & Cons of RJ11


  • Available in two configuration types
  • Easy to attach and terminate
  • Can adjust to slow-speed transmissions
  • Comes with pure copper pins with a gold coating


  • Not suitable for cables with many wires

Difference Between RJ45 vs RJ11

The following table highlights the main differences between RJ45 and RJ11.

It is used for Ethernet cables.It is used with telephone cables.
It is an 8P8C connector.It is a 6P4C connector.
It has eight wires attached to it.It has four wires attached to it.
It supports up to 10 Gbps bandwidth.It supports a maximum bandwidth of 24 Mbps.
It has a bigger size.It is smaller in size.


Q1. What is an RJ45 connector?

Ans: RJ45 is an eight-pin connector with a standardized interface that connects a computer to a LAN. This type of connector was mainly designed for telephone communications, but now it is used for a wide range of applications.

Q2. What device uses an RJ11 connector?

Ans: You can use an RJ11 connector with a variety of devices such as modem cables, phones, and ADSL lines. This type of connector is widely used for voice applications and computer networking.

Q3. What are the different types of RJ11 connectors?

Ans: There are two types of RJ11 connectors: RJ11W and RJ11C. These RJ11 connectors are used for different purposes.

Q4. What are the functions of eight pins in RJ45?

Ans: RJ45 is usually made of plastic and has eight pins on the port. Four of the pins are used for receiving and sending data, while the other four are used for other power networking devices.


So now you know how RJ45 and RJ11 connectors are different from each other. While RJ45 is an 8-pin connector, RJ11 is a 4-pin connector. You must select a connector based on your requirement.