Prox Cards vs. RFID Cards: A guide to these card types and their uses

The security industry is always evolving and updating from a tech perspective, so it can be difficult to keep up-to-date. In this post, we will look at two common technologies that have found their way into our everyday lives. These two things are often confused as they appear similar to the untrained eye, but there are some key nuances that differentiate them.

The two technologies are Proximity Cards and RFID Cards. We will be looking at what they are, how they work and, crucially, their differences.

What are Proximity Cards?

A Proximity Card is a type of contactless smart card that can be read without being inserted into a card reader. They have become very popular in recent years as ID cards used for access control. Their defining characteristics are that they are low-frequency (usually 125kHz) with a read-only format and a very short range of just a few centimetres.

They work when held within close proximity to the card reader, utilising an embedded transmitter to send information to the reader. They are excellent for controlling who can and cannot gain access to a lock. It takes only a moment for the card to communicate with the reader and the eligibility of the user to be determined.

What are RFID Cards?

RFID stands for Radio-Frequency Identification. These cards work using electromagnetic fields that enable an internal chip to be identified from varying distances. The internal chip is what enables access and tracking for users, and it usually comes in the form of a card or key fob.

The tags can be active or passive:

Active: these include a battery and are suitable for greater read distances (sometimes over 100m).

Passive: these are more common than active tags and generally come in the format of an ID card or key fob. These power up when in range of the reader's radio signal, so their range is shorter.

RFID works via a unique serial number that identifies a device when scanned by a reader. Data is stored on a microchip that connects to the antenna and transmits the identification data to the reader when in range. The reader converts the transmission into information that is sent to the host system in order to determine eligibility for access or do other things like give race results, update logistics info and more.

What are the key differences between Proximity Cards and RFID Cards?

Both technologies use radio waves as part of their functionality, but there are clear differences between Proximity Cards and RFID Cards.

Information stored

A proximity card's information storage capabilities are more limited than those of an RFID card. This means the latter is a more flexible option.

Read range

An RFID Card with an active tag can be used from a much greater distance than a Proximity Card, which only works within a few centimetres. Again, this adds far greater flexibility to the RFID Card.

Operating frequencies

The typical operating frequency of a Proximity card is low - usually 125KHz. An RFID Card, on the other hand, can have a low, high or ultra-high frequency, but typically operate at 13.56Mhz, so its potential applications are more diverse.

Line of sight

In simple terms, you do not necessarily need a line of sight to use an RFID Card. The same is technically true of a Proximity Card, but because of its very limited range, you will always be close to the reader.

Read/Write capabilities

Another fundamental difference revolves around whether the card can both read and write. Generally speaking, RFID Cards have full read/write capability, while Proximity Cards are always read-only.

Summary

Though they have similarities, you should now be clear on the differences between Proximity Cards and RFID Cards. Being able to compare them like this should help you judge which is the better option for you.

There is a lot of jargon in the security industry and it can make these decisions harder than they need to be. Our goal is to break topics down and make them easier to understand. If you need help choosing between these two types of cards, please don't hesitate to get in touch.