Before we discuss RJ11 vs RJ25, let’s know what’s RJ.
RJ stands for registered jack. It is a telecommunications network interface that can connect voice and data equipment. It is done either for a local exchange or for long-distance carrier service. These Registered Jack’s are usually called RJ in short, followed by the two digits that express the form.
The gold pin connectors that are used in telecoms, networking, and in low voltage illumination applications are actually the RJ11 and the RJ25.
The difference between these two connectors depends on the number of places on the connector and the total number of contacts. The connectors are bigger and there are more locations.
Every connector specifies the cable pattern. Both the connectors are made up of plastic that allows you to see the connections in them. There are modular connectors that connect phone networks. In the case of telecommunication networks, the RJ specification is considered.
A similarity between RJ11 and RJ25 is that both the connectors are used in the telephone industry and are made of plastic wires that can be seen from the outside. Apart from this, there are multiple differences between these. The difference between RJ11 and RJ25 is that both RJ 11 are thin and larger than the RJ25.
Comparison Table: RJ11 vs RJ25
Criteria | RJ11 | RJ25 |
---|---|---|
Physical Characteristics | RJ11 is a square-shaped lightweight compact cord. It is used to connect two computers. | RJ25 is significantly smaller than RJ11 and in square form. It is used to connect three computers. |
Configuration | The RJ11 has a configuration of 6P2C/6P4C. | The RJ25 has a configuration of 6P6C. |
Application | The RJ11 can be used for connections of handsets and modems to the computer. | The RJ25 can be used for phones. |
Purpose | RJ11 is mostly used in domestic connections. | RJ25 is mainly used in business cables. |
Connector | The RJ11 can connect one computer to another computer. | The RJ25 connects one computer to three other computers simultaneously. |

About RJ11

The RJ11 is used in multiple machines. You can normally find it on the side of a computer on notebooks. Sometimes it is on the back or in the front of the DVD tray. The key function of the socket is to communicate with the modems.
The RJ11 jack is quite wide and is found right next to the socket that looks similar. Both the sockets are connected to an adaptor (DSL internet connection) that helps to convert the machine data into a network-friendly format. There are six port channels at the base of RJ11, each of these ports has a metal stripe of copper.
This metal strip forms a bond between the plug and the sockets. In order to make calls, the telephone wire needs to be connected to the RJ11 port of the device. Network adapter-compatible call control tools are necessary to complete this setup.
These applications are known to accept faxes and archive the chosen ones as data files. It also allows you to build a voicemail and extension structure for your switchboard. The calls are usually sent for an automatic response or held in one position when the caller is listening or reading something on the computer.
About RJ25

A typical RJ25 unit is much smaller in size when compared to RJ11. Nevertheless, it must not be underestimated. On contrary to the RJ11, RJ25 has a 6P6C configuration, which enables the accommodation of up to 6 cables simultaneously.
The materials in this unit are often used to display the ties, with the help of translucent plastic. They also have copper pins which serve as electromagnetic pulse conductors. These pins are covered in gold to avoid rusting. There are multiple advantages of using the RJ25.
There are two boxes in the prototype machine, one with an IR cable attached to it and one with a microcontroller. Electricity reaches the receptacle IEC 320 of the RJ25 at the back, and a power outlet of 5-15R is to be connected to the power supply of the entertainment center.
For the use of components by switching mode, a little part of A.C. Input current is translated into 5 VDC. The power supply and the remainder pass through a switched relay and a current sensor control outlet of the machine. The IR sensor receives a remote signal of around 15 meters.
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Difference Between RJ11 and RJ25
1) Usage
the RJ11 cable adapter is used for the internet, ADSL, and modem cable applications. On the other hand, RJ25 jackets are used for telephone systems and networking.
2) The number of slots
The RJ11 connector has four slots, whereas RJ25 has 6 slots.
3) The number of positions
The RJ11 has six positions which consist of four wires. On the other hand, RJ25 has 6 cable positions.
4) Types of configuration
RJ11 has the configurations 4P4C and 6P4C. RJ25, on the other hand, has the configuration 6P4C. You will also find 6 wires in the conduit which can fit all the available slots.
5) Size
The RJ11 is visually smaller than the RJ25. On the other hand, the RJ25 is physically bigger than RJ11.
6) Shape and Weight
RJ11 is more compact because of its square form. On the other hand, the RJ25 is round, light, and compact.
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Summary
RJ11 is a licensed telecommunication jack. It is a modular connector, wired with two connections, and has a total of 6 positions open. In countries like the USA, this kind of setup is used for single telephones.
You will also find a 6P4C adapter attached to a power telephone lamp with an extra pair of wires. For specific devices, connectors like RJ11 and RJ25 are very efficient.
RJ11 is unique because it can make three connections at once. The RJ25 can add 6 wires on one go and connect three devices together. This is why RJ25 is a better producer than RJ11. Some other pros of choosing RJ25 are that:
● RJ25 is strong and durable.
● It can handle 6 wires at a go.
● It has copper pins that are gold-coated that keeps them from rusting.
● It can connect 3 devices at the same time.
One of the cons of RJ25 is that it cannot handle heavy data transitions.
Naomi is an educator with 2 decades of experience working with children of all ages. She is a keen observer of the magic and importance of Maths in our daily lives. Follow me on Linkedin