Difference Between Rj12 and Rj25 (With Table)

Rj11 and Rj12 are generic telecommunication network interface which connects long-distance or local exchange with voice and data communication. There are lots of registered jacks, and they are used for different purposes. These connectors are often called modular connectors as they have made phone connections easier these days, and due to more locations, the connection is bigger and wide.

Rj12 vs Rj25

The difference between Rj12 and Rj25 is that they are mostly similar but have different characteristics. Rj12 and Rj25 are mostly used in telephone companies and industries. They both are used in telephone networks and also in data networks in computer networks. Both the registered jack is in different shape and are transparent as we could see what is in it.

Rj12 has three pairs of copper strands which allow exchanging information on three different lines. RJ12 has six slot connectors, and it is visible. Rj12 is made up of thin cables and connections, and they are fully made up of plastics. Rj12 has 6p, which means it has six connectors in it.

When compared to that of size, Rj25 is smaller than Rj12, but it is powerful as well. It is in a square shape, and it is light weighted, and they are used in telephone and network communication. Totally six copper wires can be handled at a time as the jack is set to 6p6c. Rj25 has six attachments and six locations.

 Comparison Table Between Rj12 and Rj25

Parameters of ComparisonRj12Rj25
Physical characterRj12 is big in size and it is compact square-shaped.Rj25 is small in size and it is small square-shaped.
UsesIt is used mostly in systems and phones for contact.It is used in telephone devices for contact.
ConfigurationRj12 configuration is 6P2C.Rj25 configuration is 6P6C.
ConnectorRj12 is used to connect one computer.Rj25 is used to connect three computers simultaneously.
WeightIt is slightly heavy from other registered jack.It is light.

What is Rj12?

Rj12 is a registered jack that is light and is totally made up of plastic. Wires inside it are visible from the outside. It is mostly seen in computers and laptops for their data connection, and it is seen near DVD trays on personal computers. The socket key is to communicate with modems for the internet.

Rj12 is used with an adapter, and it is slightly big in size when compared to other registered jacks. RJ12 has three copper strands that are used to exchange information. The connector used to connect Rj12 is a six-slot connector. It is mostly used in the connectivity of telephone lines in companies, and it is used in many places.

The Rj12 is a 6PC6 connector where the wires are in different colours, and they are visible from the outside. Rj12 is made up of thin copper cables. There are Rj12 telephone systems and PBX, and most of the PBX offers phone tracking and many more features where the Rj12 key systems don’t.

To make calls, telephone lines may be connected to the RJ12 port in a device, and this process requires an adapter and control tool. The Rj12 is available on many machines for data connection and call connection. It is lightly weighted and used for multipurpose.

What is Rj25?

Rj25 is the smallest, but it is one of the most powerful connectors, as we should not underestimate it. The material is often displayed ties using translucent plastic. The electromagnetic pulse conductor is produced by copper pins that are available in it. Gold is covered around it as it protects from rusting.

It has a 6P6C configuration as it is able to connect six cables simultaneously, and it can also be connected to three computers simultaneously. It is thin and small, and it is light weighted. It is mostly used for data and communication purposes, and it is mainly used in business cables.

The pros of Rj25 can accommodate up to six wires at a time. The prototype machine has two boxes which are a microcontroller and power controller. An IR cable is also attached to it. The Rj25 is more powerful and long-lasting. It is small in size and square in shape, and there are also wires in this connector that fill all the slots.

Rj25 is compact and is round and lighter when compared to Rj12. It is covered with gold as it prevents rust. Rj25 has six slot plugs and can be connected to different computers. RJ25 jacks are used in telephone systems and used in networking connections for communications, and Rj25 is a six-slot plug.

Main Differences Between Rj12 and Rj25

  1. Rj12 is a four-slot connector and whereas Rj25 is a six-slot connector as it can be connected to six computers at a time.   
  2. Rj12 is big in size and compact in shape, and Rj25 is small in size and is a small square shape.
  3. Rj12 is mostly used in systems and phones for communicating, and Rj25 is used in phones for contact.
  4. Rj25 has six cables, whereas Rj12 has four cables of six positions.
  5. Rj12 has four slot connectors, and Rj25 has a plug of six slots.
  6. Rj11 is compact and square in shape, and Rj25 is rounder, lighter and more compact.


The registered jack is of different types and is used for communication purposes. They are connector wires which are used worldwide other than the USA. These are often used for single telephones and computers. Rj11 has three devices, and it is unique on its own and Rj25 can manage 25 devices at a time.

Both the registered jacks are licensed and are commonly used in our day-to-day life. Rj25 is better than Rj11 as it is light and thin when compared. Rj11 has two lines, and Rj25 has three lines. Rj11 is a connector with four slots, and Rj25 has six cable slots.


  1. https://www.leadsdirect.co.uk/technical-library/pinouts-wiring-diagrams/what-is-the-difference-between-rj10-rj11-rj12-and-rj45-connectors/
  2. https://www.mouser.in/Connectors/Modular-Connectors-Ethernet-Connectors/_/N-5g3y?P=1yzvt47
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