demagnetized key fob


If you manage access at your property with a key card or key fob system, one thing is certain. Eventually, residents start to have technical problems with their fobs. One of the most common is a demagnetized fob. Here’s a quick guide to help you fix a demagnetized key fob.

We also cover reasons why a key fob might have been demagnetized and offer alternatives to magnetic fobs.

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How do you fix an unresponsive key fob?

To fix an unresponsive key fob, put it back into your property’s fob programmer. That’s it!

Additionally, when you hand the fob or badge back to the resident, gently remind them to keep their magnetic key fob away from sources of magnetic interference to prevent this from happening again.

If the fob still doesn’t work after that, it might have another problem. This can often be attributed to normal wear and tear. If you’re not sure how to make a key card work again, take a fresh fob and use your programmer to give it all of the same access permissions as the old one.


Watch how ButterflyMX works:


Can key fobs get demagnetized?

Unfortunately, yes, key fobs can get demagnetized — and it happens often.

While magnetic access is secure, it depends on those magnetic particles staying in the same configuration. And with so many sources of magnetic force in the world, it’s common for particles to accidentally reverse their polarities. As a result, they render the whole pattern illegible.


Why a key fob might have been demagnetized

A magnetic key fob can become demagnetized due to exposure to an outside magnetic force that wipes its data.

Sometimes, a fob might come close to a battery-powered electromagnetic device. As a result, it may have all of its data wiped that way. Other times, proximity to a simple magnet is enough to demagnetize a fob.

Common items that might demagnetize key fobs include:

  • Cell phones
  • TVs
  • Laptops
  • Magnetic clasps on purses or wallets
  • Security tags adhered to clothing in stores

To understand why demagnetization happens, it’s important to learn how magnetic key fobs work. With this information, you might be able to soothe a frustrated resident!


fixing a demagnetized key fob for residents


How do magnetic key fobs work?

Magnetic key fobs work by encoding credential data into a magnetic stripe present on the fob. This magnetic stripe, or magstripe, is actually made of millions of magnetic particles. When one of these particles is magnetized, it becomes either north-facing or south-facing.

While a choice between two states might not sound like much, fob encoders create unique patterns over the millions of particles on the entire magstripe. So, each time you use your key card machine to program a fob, you change these polarities.

For example, a resident using their key fob holds it up to a credential reader. Readers scan information stored in a fob by sending out a quick burst of voltage and recording what comes back.

Then, if the information the reader receives matches the credentials in the reader’s internal database, the reader considers the card valid and triggers the lock to open.


Alternatives to magnetic key fobs

Are you tired of re-magnetizing your residents’ fobs? Luckily, there’s a solution!

In fact, you can still reap the benefits of electronic access control without relying on magstripes.

Instead of dealing with magnetic fobs, you might:

  1. Choose fobs that use a different technology
  2. Invest in keyless access control


rfid or bluetooth instead of demagnetized key fob


1. Choose fobs that use a different technology

Different technologies that aren’t as vulnerable to interference can power key card systems. So, if you still want to hand out key fobs to your residents, choose one of these. For example, you can buy RFID or Bluetooth fobs that exchange data with readers using radio waves instead of magnetization

With an RFID or Bluetooth fob, magnetic interference might not be an issue anymore. However, you do open yourself up to a host of other complications.

In some cases, these newer fobs come with their own batteries and transmission capabilities. They’re more sophisticated, but you might have to spend more money on an RFID fob than a magnetic fob.


2. Invest in keyless access control

Even if a fob is technologically reliable, you’ll run into problems if residents use them every day. You still might need to send them out for repairs. And because fobs are so small, your residents might lose them — requiring you to constantly order and program replacements.

Luckily, today’s access control systems offer credential solutions that free residents from carrying keys at all.


entrance intercom butterflymx


The best keyless access control system

You may be looking to augment fob access with alternative ways to open doors or gates. Or, maybe you’re looking to bypass fobs entirely. Whatever your goal, your best option is the ButterflyMX access control system.

ButterflyMX’s ecosystem of intercoms, keypads, elevator controllers, and more serves tens of thousands of buildings around the world.

Instead of dealing with fobs that are easily lost and demagnetized, save money on fob replacement costs by empowering your residents to open doors with their phones. With ButterflyMX, access becomes as easy as opening an app on a resident’s smartphone and swiping.

However, if you’re still interested in keeping fob access, we gladly offer that too. Our network of integrators and installers can install our seamless fob system. Or, they can save you installation costs by integrating our system into your existing one.



  • How do you fix a demagnetized key fob? Re-encode it with your property’s card magnetizing tool. If that doesn’t work, you might have to replace that fob entirely and rekey a new fob with the same information.
  • A key fob might have been demagnetized through contact with common magnetic items, like TVs, cell phones, or metal clasps on clothing or bags.
  • Magnetic key fobs work by encoding a unique pattern into millions of magnetic particles. However, these patterns are easily disrupted by everyday magnetic objects.
  • Instead of depending on magnetic key fobs, you can purchase key fobs that are powered by other technology, like RFID or Bluetooth. Or, you can embrace keyless access.
  • The best keyless access system is ButterflyMX’s swipe-to-open smartphone app — but we also offer fobs if that’s your preference.


keyless access with butterflymx cta


Ferdison Cayetano

I’m a proptech enthusiast from New Jersey who’s looking forward to the innovations that will revolutionize real estate.