What Material Will Block GPS Signal

Wondering what material will block a GPS signal?

The answer is pretty much any dense material like aluminum foil, concrete, or metal can block the signal from a GPS tracking device.

If you’re worried that someone might be tracking your location without your consent, the best thing you can do is manually check your phone for location tracking apps, and then inspect your car for a hidden GPS tracker.

Large buildings, wooden covers, heavy metals, or aluminum foil will block the signal to the satellite, making it impossible for anyone to see where you are. However, you’ll have to find the device first.

You’re probably better off just getting a GPS signal jammer. These devices “scramble” the signal, confusing the tracking device and making you “invisible”. They’re a lot more reliable than some Reynolds Wrap.

In the rest of this article, we’ll dive into blocking signals in depth with different kinds of materials and show you step-by-step how to do it using aluminum foil. We’ll also cover some very important legal regulations you need to know to stay on the right side of the law!

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5 Materials That Block GPS Signals

1. Aluminum Foil

Ah, aluminum foil. You always knew that there was some use for it. Now you know.

Aluminum foil is surprisingly effective at blocking GPS signals, and it’s all thanks to a concept known as a Faraday cage. When you wrap a GPS tracker or similar device in aluminum foil, it can block the radio signals the device relies on, making the GPS tracker essentially useless.

So, what’s happening here? The aluminum foil acts like a makeshift Faraday cage—a type of container made of conductive material, like metal, which blocks electromagnetic fields. When GPS signals hit the foil, it creates currents in the material, which then produce an opposing field that cancels out the GPS signals.

Here’s how it breaks down:

• Aluminum Foil as a Shield: Wrapping foil around a GPS device creates a barrier that blocks the radio signals.
• Faraday Cage Effect: This works just like a Faraday cage, where the conductive material cancels out the signals trying to pass through.
• Impact on GPS Tracking: As a result, the GPS tracker loses its signal, disrupting its ability to function properly.

Understanding how something as simple as aluminum foil can interfere with GPS signals highlights the need to be mindful of how you handle and position GPS devices. Whether you’re shipping something, using GPS for personal navigation, or any other tracking purpose, knowing this can help you avoid unintentional signal loss and ensure your GPS works as intended.

Here’s a quick step-by-step guide on wrapping a GPS device in aluminum foil to block its signal:

1. Gather Materials: Get a piece of aluminum foil that’s large enough to fully cover the GPS device. You may need additional layers for better signal blocking.
2. Prepare the GPS Device: Make sure the GPS device is turned off, if possible, to ensure no data transmission occurs during the wrapping process.
3. Wrap the GPS Device: Place the GPS device in the center of the foil and fold the edges over it, ensuring the entire device is completely covered. Smooth out any wrinkles to avoid gaps where signals could potentially pass through.
4. Secure the Wrapping: Once the device is fully covered, add a second layer of foil for extra security. Ensure the foil is snug and secure, with no openings.
5. Test the Signal Block: To check if the signal is fully blocked, try locating the GPS device with a tracking app or device. If it’s not detectable, the foil is effectively blocking the signal.
6. Store or Hide the Wrapped Device: Place the wrapped GPS device in a secure location where it won’t accidentally get unwrapped.

IMPORTANT NOTE: If your GPS tracking device is there for a legitimate reason, you may be breaking the law by removing it. See the section on legal ramifications of GPS jamming below.

2. Natural Barriers Like Forests And Mountains

Forests and mountains can be pretty effective at blocking GPS signals, which is why your GPS tracker might struggle in these areas. The thick trees in forests and the sheer size of mountains can get in the way of the signal, making it hard for your device to connect with satellites.

If you’re trying to block your GPS signal, sticking to areas with dense tree cover or rugged mountains is a good bet. Think about those times when you’ve been out on a hike, deep in the woods, or surrounded by mountains, and suddenly your GPS or phone just loses signal. That’s exactly what happens when natural barriers get in the way.

But here’s the thing—if you’re heading into these areas, don’t just rely on your GPS. It’s always smart to have a backup, like a good map and compass, just in case your GPS cuts out. That way, you’ll be prepared and won’t get caught off guard when the signal drops.

3. Metal Boxes

Metallic structures (or metal boxes), like the ones found in cars, can block GPS signals.

In fact, that’s one of the main reasons trackers malfunction from time to time - they can’t connect to the network because the car’s frame gets in the way.

Here’s what’s happening: The metal components of the car act as barriers. These barriers make the GPS antenna and receivers unable to communicate effectively with GPS satellites. This is also why you shouldn’t hide a GPS tracker in the trunk of a vehicle.

Here’s a tip: If you’re renting a car, put the GPS device where it has a clear view of the sky, away from metal parts that could block the signal. We recommend the dashboard or underneath the car (GPS signals can reflect off the ground or other surfaces).

Tip: If you think someone might be tracking you without your consent, use a GPS detector to search different areas under your car, inside the dash, or inside the front end. Smart stalkers will know not to place the device inside the trunk. Always think like the person you’re trying to catch!

4. Concrete

Concrete structures can totally block your GPS signal, especially in places like underground parking garages or buildings with thick concrete walls. You’ve probably noticed that when you park your car in one of these spots, you never get a signal. Right? Well, it’s time to use that to your advantage.

If you’re trying to hide from someone (we won’t ask why), try to find a concrete parking garage. If it’s underground, double points.

In an underground parking garage, the concrete walls, ceilings, and floors create a maze that GPS signals just can’t get through.

Even above ground, concrete buildings can reflect GPS signals, making your location seem off or causing your GPS to give you wrong directions.

So, what can you do if concrete is messing with your GPS signal? If you’re in an underground structure, just know that your GPS will probably reconnect once you get back outside. For driving, consider using a GPS device with preloaded maps that can guide you even when the signal drops, or keep a traditional map handy as a backup.

Related Article: Can GPS Be Traced Back To Owner?

5. Large Buildings

Large buildings like skyscrapers can block GPS signals by obstructing the line of sight between the GPS device and satellites. So, if you’re trying to stop someone from tracking your location, try to drive to a place with a lot of tall buildings.

The dense materials in these structures, like concrete, steel, and glass, absorb and reflect the GPS signals, making it difficult for the device to connect. This interference creates "dead zones" where GPS tracking becomes unreliable or even impossible.

Pro Tip: If you’re trying to hide from GPS tracking, move through areas with tall buildings or stay close to structures made of dense materials like concrete or steel. The more these materials surround you, the more likely they are to disrupt the GPS signal. Just be mindful that while this can scramble the signal, it's not foolproof. For added security, consider combining this with other methods, like disabling the GPS device or using a GPS jammer (where legal).

BONUS: GPS Jammers

If you want something that’s guaranteed to block a GPS tracking signal, GPS jammers can block signals by disrupting GPS communication anywhere at any time. These devices scramble GPS signals, making it impossible for the system to know where you are.

Is it Legal to Block a GPS Signal?

Yes, it’s legal to block a GPS signal if someone has planted a device illegally to track your location.

For example, if your crazy ex is trying to follow you, of course you’re legally allowed to hide. You have the right to protect your privacy from unauthorized surveillance.

However, it’s illegal to block the signal from a legally placed GPS tracker. For example, employers, law enforcement, or anyone with proper legal authority can use GPS tracking, and interfering with these devices can lead to serious legal consequences.

GPS jammers are usually illegal in most places. The problem is they don’t just block the signal to one device—they can mess with GPS signals over a pretty big area.

This means they can disrupt not only the tracker you’re trying to block but also other devices and services that depend on GPS (like planes!).

It’s always a good idea to check your local laws before trying to block or jam any GPS signals.

What Material Will Block GPS Signal – Frequently Asked Questions