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Does Aluminum Foil Block GPS Signal?

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Does Foil Block GPS?

There have been several explanations of the effects of aluminum foil on GPS signals. In movies, you may have seen that the vigilante hero on the run disables GPS tracking on their phone or tablet by wrapping it in aluminum foil. The idea behind it is that aluminum foil can be used as a signal jammer but is there any truth to this? Does aluminum foil have the ability to block GPS or cell phone signals? First, we need to understand how GPS tracking works and in what ways can it be disabled through various techniques, including this use of aluminum tin foil!

Before we endeavor into figuring out if aluminum foil can disable GPS tracking devices, it is vital to grasp an understanding of what GPS systems are and how do they function. A working definition of a GPS tracker is that it is a tool that determines the location of a specific item or asset in real-time. GPS tracking devices are usually compact and are attached to the asset that needs to be navigated or surveilled. A GPS device can take the form of a cell phone or it can be a GPS tracker. In either case, GPS tracking has a plethora of useful purposes in various walks of life. For instance, entrepreneurs and managers can use a tracking device to ensure the safety and security of fleets, vehicles, and valuable items by continuous monitoring. On the other hand, for domestic purposes, GPS trackers are handy tools used for keeping an eye on children, pets, and the elderly to prevent harm or any unwanted situation.

Fun Fact: GPS tracking systems operate by transmitting data over cell towers to where the live location of a vehicle, person, or asset can be viewed remotely in real time! 

All live GPS trackers work in the same fashion. They employ a method called trilateration to figure out the location, speed, and altitude of an item. GPS devices work in tandem with satellites that use sophisticated technology to broadcast the position and time of the GPS device. In essence, GPS systems calculate the time and distance it takes for a signal to travel from the device to a satellite so as to estimate the exact location of an object. A typical GPS tracker will make use of data from four or five satellites to form accurate real-time navigation or positioning. Having access to more satellites will further enhance the correctness of a tracker.

Related Content: What Is The Best Geofencing GPS Tracker?

Does Aluminum Foil Block Cell Phone Signals?

Other than the ways mentioned above, wrapping aluminum foil around a GPS device is a successful and perhaps, the most common way to block GPS signals. Aluminum foil is a good conductor of electricity that induces a phenomenon known as Faraday Cage to disrupt the reception of GPS signals to and from a GPS device. Thus, when an aluminum foil is wrapped around a cell phone, it creates a barrier and prevents radio waves from reaching the cell phone. Like all metals, aluminum possesses the quality of attenuation effectiveness. This gives aluminum foil the ability to absorb electromagnetic waves such as radio signals of a GPS device.

Aluminum is a proficient GPS blocker due to its high attenuation effectiveness capability. Because of this, aluminum foil does not need to be very thick to be effective. However, to ensure that it blocks signals completely, we recommend that you wrap your phone in aluminum foil tightly so there are no gaps or holes to reduce the efficacy of the shield.


Aluminum foil does have the ability to act as a GPS blocker. GPS signals are radio waves that travel from a GPS tracking device to a satellite and by creating a Faraday Cage barrier between the two, an aluminum foil disorders the transmission path of the GPS signals. The high attenuation ability of aluminum to absorb signals makes it an ideal and popular GPS blocker. That being said, there are other methods of preventing GPS tracking devices from working as well. GPS signals can be cut off by a GPS jammer that causes interference in the signal transmission path. Besides that, metal and concrete layering can also obstruct GPS signals as they form an impenetrable medium for radio waves.