Yes, Faraday bags completely block GPS trackers by stopping the 1.575 GHz signals from GPS satellites. When a GPS tracker is sealed inside a properly made Faraday bag, it cannot receive location data from satellites or transmit that data to whoever’s monitoring it. The tracker goes silent and stops updating location entirely.
Note: This article covers GPS trackers that use satellite signals. For Bluetooth trackers like AirTags that don’t use GPS, see our guide on Bluetooth blocking.
But here’s what catches most people off guard: GPS blocking is actually one of the easiest jobs for a Faraday bag. Those satellite signals travel 12,000 miles through space and arrive at Earth incredibly weak. Your phone barely detects them even in perfect conditions. Compare that to cellular signals that blast from towers just miles away with enough power to penetrate concrete buildings. If a Faraday bag struggles to block GPS, it’s basically useless for everything else.
The metal shielding in the bag intercepts those weak satellite signals before they reach the tracker. No GPS signal means no location data. No location data means the tracker can’t tell anyone where you are. Simple physics makes tracking impossible while the device stays bagged.
How GPS Trackers Actually Work
GPS trackers receive signals from satellites orbiting Earth. These satellites constantly broadcast their location and the current time. Your tracker picks up signals from multiple satellites (usually 4 or more) and calculates its position based on how long those signals took to arrive.
This positioning happens entirely through receiving satellite signals. The tracker doesn’t transmit anything to the satellites. It just listens and calculates.
Once the tracker knows its location, it needs to report that information. This is where cellular, WiFi, or other wireless technologies come in. Most GPS trackers use cellular connections to transmit location data to a server or directly to whoever’s monitoring the device.
Some trackers log location data internally and transmit it later. Others send real-time updates constantly. Either way, they need wireless communication beyond just GPS to be useful for tracking.
A Faraday bag blocks both parts of this process. The tracker can’t receive GPS signals to determine location, and it can’t transmit location data even if it somehow had it.
What Actually Gets Blocked
GPS trackers use multiple wireless technologies depending on their design. A comprehensive Faraday bag blocks all of them.
Cellular GPS Trackers (Most Common)
These are the most common type. The device receives GPS signals for positioning and uses cellular networks (4G/5G) to transmit location data. Think of tracking devices for cars, personal safety devices, or hidden trackers.
A Faraday bag blocks both the GPS reception (1.575 GHz) and the cellular transmission (typically 700 MHz to 2.5 GHz). The tracker can’t figure out where it is and can’t report anything even if it could.
I’ve tested this with everything from cheap $10 Amazon trackers to professional fleet monitoring devices. Once properly bagged, they all go silent. The expensive ones don’t have some magic radio that penetrates shielding. Physics works the same way for all of them.
WiFi-Enabled Trackers
Some trackers use WiFi for location reporting, either by transmitting data over WiFi networks or using WiFi access point information for location approximation (WiFi positioning).
Faraday bags block WiFi frequencies (2.4 GHz and 5 GHz) along with GPS. The tracker loses both GPS satellite signals and WiFi connectivity.
Bluetooth Trackers (AirTags, Tiles)
These don’t use GPS satellites directly. Instead, they rely on Bluetooth to communicate with nearby smartphones, which then report the tracker’s location using the phone’s GPS and internet connection.
Faraday bags block Bluetooth signals (2.4 GHz), preventing the tracker from communicating with any phones. No communication means no location reporting, even though these devices don’t technically use GPS themselves.
Satellite Communicators (Rare)
Some high-end trackers use satellite communication networks like Iridium or Globalstar instead of cellular. These are rare and expensive, used mainly in remote areas without cell coverage.
Quality Faraday bags block these satellite communication frequencies along with GPS. The exact frequencies vary by system, but they typically fall within the range that comprehensive Faraday bags handle.
For a complete breakdown of all frequencies that Faraday bags block, see what frequencies Faraday bags block.
When You Actually Need GPS Blocking
Understanding why people block GPS trackers helps clarify what you need from a bag.
Dealing with Unwanted Trackers
AirTag stalking has become common enough that Apple built detection features into iOS and Android. If you find a tracker that isn’t yours, a Faraday bag immediately stops it from reporting your location while you figure out what to do with it.
This gives you time to go to police, disable the device, or take other action without the person who planted it knowing your movements. The tracker stays intact as evidence, but it can’t be used for continued stalking.
I’ve talked to people who found AirTags hidden in their cars, in purses, even sewn into coat linings. First thing I tell them: bag it immediately, then deal with it. Don’t give the person tracking you any more data while you figure out next steps.
Privacy During Sensitive Activities
Some people need location privacy for legitimate reasons. Journalists meeting sources, lawyers meeting clients, activists organizing, or anyone whose location data could compromise someone else’s safety.
Bagging devices with GPS prevents any location tracking during sensitive meetings or travel. Your whereabouts stay private without relying on software settings that may or may not actually work.
Corporate Vehicle Tracking
Some companies track employee vehicles using GPS devices. While this might be legal depending on your jurisdiction and employment contract, you might not want tracking during personal time.
Bagging the GPS tracker (if you can access it) stops location reporting. Be aware this might violate company policy or employment terms depending on your situation. I’m not a lawyer, but I’ve seen people get fired for this. Know what you’re risking.
Digital Forensics and Security Testing
Law enforcement seizing GPS trackers needs isolation to preserve evidence and prevent remote wiping or data tampering. Security professionals testing GPS tracking devices need to verify functionality without broadcasting location.
Faraday bags provide documented, reliable blocking for both scenarios.
Testing GPS Blocking
Here’s how to verify your bag actually works. Don’t trust manufacturer claims. Test it yourself.
The Smartphone GPS Test
Open a GPS or mapping app that shows satellite connections and location accuracy. Note your current location and how many satellites are connected (usually 4-8).
Seal your phone in the Faraday bag. Wait 30 seconds. The app should lose all satellite connections. Location accuracy should drop to nothing or show an error.
Leave it bagged for 2-3 minutes, then remove the phone. The GPS should show your location from before you bagged it, not your current location. It takes time for GPS to reacquire satellites and calculate a new position.
If your phone shows your current location immediately after removing it from the bag, the bag didn’t block GPS. The phone was tracking you the whole time.
The Tracker Movement Test
If you have an actual GPS tracker, check its current location in the monitoring app or website. Seal the tracker in your Faraday bag. Move to a different location (drive a few blocks or walk to another building).
Check the monitoring app again after 5-10 minutes. The location should still show where you bagged the tracker, not where you moved it. The tracker couldn’t receive GPS signals or transmit updates while bagged.
The AirTag Test
For Apple AirTags or similar Bluetooth trackers, check the tag’s location in the Find My app. Note the location and that it’s showing as “with you” or nearby.
Seal the AirTag in your Faraday bag. Move to a different location. Check Find My after several minutes. The location should still show where you bagged it, not your current location. The tag can’t communicate with any phones to update its position.
The first time I tested an AirTag in a bag, I was surprised how fast the signal dropped. Within 5 seconds, Find My showed it as disconnected. Good bags work immediately. If you seal an AirTag and it takes 30 seconds or a minute to disconnect, your bag is marginal at best.
The Satellite Connection Test
Many GPS apps show not just your location but how many satellites are currently connected and their signal strength. This is useful for precise testing.
Watch the satellite count with your device unsealed. It should show 4-8 satellites with varying signal strengths. Seal the device. The satellite count should drop to zero within seconds. All signal strength indicators should disappear.
For comprehensive testing methods across all signal types, see how to test a Faraday bag.
What Cheap Bags Miss
Budget GPS tracker pouches often fail in predictable ways. I’ve tested dozens of cheap bags and the failure patterns are consistent.
Inadequate GPS Frequency Blocking
Some cheap bags use thin single-layer material that doesn’t provide enough attenuation at GPS frequencies. The signal gets weakened but not completely blocked.
Your tracker might show degraded accuracy or intermittent satellite connections instead of complete signal loss. This partial blocking is worse than no blocking because you think you’re protected when you’re not.
Poor Cellular Blocking
Even if a bag blocks GPS signals adequately, it might fail to block the cellular frequencies the tracker uses to report location. The tracker can’t get GPS satellite signals but might use cell tower triangulation or WiFi positioning as a backup.
Without blocking all communication methods, the tracker can still report approximate location even without GPS. Here’s what catches people: they bag the tracker, see GPS fail in testing, and assume they’re protected. Meanwhile the cellular radio is still transmitting location via tower triangulation. You’re bagged and still being tracked.
Seam and Closure Failures
GPS signals have relatively long wavelengths (about 19 cm for L1 band), but poorly sealed seams can still leak signal. More importantly, if seams leak GPS, they definitely leak the shorter wavelength cellular and WiFi signals.
The bag might appear to block GPS in testing but fails on the cellular transmission that actually matters for tracking.
Inconsistent Performance
Some bags block signals when new but degrade with use. The conductive material wears thin, develops gaps, or loses effectiveness. Testing once when you buy the bag isn’t enough. Periodic retesting ensures continued protection.
I’ve had people tell me their bag stopped working. Turns out the bag is fine. The Velcro is shot from daily use and they’re not getting a seal anymore. Materials degrade. Don’t trust old bags without retesting them.
For understanding what construction details actually matter, see single layer vs multi-layer Faraday bags.
Common Mistakes People Make
The number of times I’ve seen people screw this up has taught me what to watch for.
Not Sealing Properly
Most bag failures? Improper closure, not inadequate shielding. Roll-top bags need 3-4 complete rolls. Flap closures need full overlap. People get lazy with the closure and wonder why their bag doesn’t work.
This is the most common failure I see. The bag works fine. The person using it doesn’t seal it right. I watched someone do two rolls on a roll-top bag instead of four and complain the bag was defective. The bag was fine. User error isn’t covered by warranty.
Testing Once and Forgetting
Bags degrade. Materials wear. Closures lose grip. Testing when you first buy the bag doesn’t guarantee it still works six months later.
Test periodically, especially if you actually rely on the blocking. I retest my daily-use bag every few months. Takes five minutes. Beats discovering it stopped working when I actually need it.
Bagging One Device, Missing Others
You bag your phone but forget about your smartwatch. Or you bag the obvious tracker but miss a second backup device. Sophisticated tracking sometimes uses redundancy.
If you’re actually worried about tracking, think through all your devices. That fitness tracker on your wrist? Still broadcasting. Those wireless earbuds? Still pinging. Your car’s built-in navigation? Still reporting to the manufacturer. Bag everything or bag nothing.
Assuming Partial Blocking Works
If your tracker shows degraded signal instead of no signal, the bag failed. Don’t rationalize that “weaker is good enough.” It’s not. The tracker still functions, just with reduced accuracy.
This is worse than no blocking because you think you’re protected when you’re not. The tracker can’t get GPS satellites, but it’s using cell tower triangulation to report approximate location. The bag failed. Period.
GPS Blocking vs GPS Jamming
These are different technologies with different legal statuses, and people confuse them constantly.
Faraday Bags (Legal Everywhere)
Faraday bags passively block signals by creating a physical barrier. They don’t transmit anything or interfere with other devices. This is completely legal everywhere.
You’re simply putting your device in a shielded enclosure. The bag doesn’t affect GPS signals outside itself, doesn’t interfere with satellites or other people’s devices, and doesn’t violate any regulations.
GPS Jammers (Illegal)
GPS jammers actively transmit noise on GPS frequencies to overwhelm legitimate signals. These devices interfere with GPS reception for everything nearby, not just your device.
GPS jamming is illegal in the United States, Canada, European Union, and most other countries. It interferes with navigation systems, emergency services, and commercial operations. Penalties can be severe.
I’ve seen someone get a $30,000 FCC fine for using a GPS jammer in their company truck because they didn’t want the boss tracking them. The jammer interfered with navigation at a nearby airport. Don’t be that person. Use a Faraday bag. It’s legal and it actually works.
Using a Faraday bag is the legal way to prevent GPS tracking on your own devices. It affects only what you put inside the bag and doesn’t interfere with anything else.
Choosing GPS Blocking That Works
For GPS tracker blocking, you need comprehensive frequency coverage, not just GPS-specific shielding.
Look for Faraday bags that specify blocking from at least 10 MHz to 6 GHz. This ensures coverage of GPS (1.575 GHz), all cellular bands (700 MHz to 2.5 GHz), WiFi (2.4 and 5 GHz), and Bluetooth (2.4 GHz).
Multi-layer construction provides better signal attenuation across all these frequencies. Single-layer bags might block GPS but fail on cellular or WiFi.
Check for actual testing data at GPS frequencies. Manufacturers who publish attenuation measurements at 1.575 GHz are more likely to have products that actually work. If they just say “blocks all signals” without numbers, that’s a red flag. For understanding performance specifications, see Faraday bag attenuation.
Verify seam construction and closure mechanisms. GPS has relatively long wavelengths, but the cellular and WiFi signals you also need to block have shorter wavelengths that escape through smaller gaps.
Size the bag appropriately for what you’re blocking. A bag barely large enough for the tracker makes proper sealing difficult. You need extra room to fold and seal it correctly.
For comprehensive buying guidance, see how to choose a Faraday bag.
The Limitations You Need to Know
Faraday bags block GPS trackers only while the device is sealed inside. The moment you remove it, all functionality returns. This isn’t like airplane mode that you can forget to turn back on. The device works the second it’s unsealed.
If someone has hidden a GPS tracker on your vehicle and you don’t find it to bag it, the bag doesn’t help. You need to locate the device first. Physical search matters more than having a bag ready.
Some sophisticated tracking systems use multiple redundant trackers or combine GPS with other location methods like cellular triangulation. Bagging one tracker might not stop all tracking if multiple devices are present.
Battery-powered trackers continue trying to get signals and transmit data while bagged. This drains the battery faster than normal operation. For long-term storage of a tracker, consider removing the battery if possible. A tracker that normally lasts three months might die in three weeks while bagged because it’s constantly searching for signal.
The bag provides technical blocking but doesn’t address the underlying situation. If someone planted a tracker on your property, that’s a legal and personal safety issue requiring more than just signal blocking. Technical solutions don’t fix human problems.
Common Questions
Will my GPS tracker know it’s being blocked?
The device will recognize it can’t receive GPS signals or transmit data, but this looks exactly like being in a basement, tunnel, or other location with no reception. The tracker can’t tell the difference between a Faraday bag and natural signal loss.
From the tracker’s perspective, you drove into a parking garage and the signal cut out. It doesn’t know about the bag.
Can GPS be blocked but cellular still work?
Not with a Faraday bag. These block electromagnetic signals across a broad frequency range. You can’t selectively allow cellular while blocking GPS. If you need that specific configuration, you’d need GPS-specific jamming technology, which is illegal in most places.
What about assisted GPS?
Assisted GPS uses cellular networks to speed up GPS acquisition by providing satellite location data. Faraday bags block both the GPS signals and the cellular assistance, so assisted GPS doesn’t help the tracker.
How long does GPS take to reacquire after removing from the bag?
Usually 30 seconds to 2 minutes depending on conditions. The device needs to find satellites, receive their signals, and calculate position. This is called “time to first fix.” A device that was recently tracking might reacquire faster than one that’s been off for hours.
If your device shows location instantly after removal, it was tracking you the whole time. The bag didn’t work.
Do aluminum buildings block GPS like Faraday bags?
Buildings with metal structures do block GPS signals, which is why GPS often doesn’t work well indoors. But this blocking is inconsistent. Faraday bags provide reliable, complete blocking every time when properly sealed.
Making GPS Blocking Effective
Quality Faraday bags completely block GPS trackers by stopping satellite reception and wireless transmission. The same shielding that handles cellular and WiFi easily stops the weaker GPS signals.
Test your bag with GPS-enabled devices before you need it. Verify that satellite connections drop and location stops updating when devices are properly bagged. Don’t wait until you actually need it to discover your bag doesn’t work.
Understand what type of tracker you’re dealing with. GPS-only trackers need GPS blocking. Cellular GPS trackers need both GPS and cellular blocking. Bluetooth trackers need Bluetooth blocking. Get a bag that handles all wireless technologies to cover any tracker type.
Use GPS blocking as part of a comprehensive approach to privacy and security, not as a standalone solution. Technical blocking works, but addressing why tracking is happening matters more for long-term safety.
For legitimate privacy needs, GPS tracker blocking with Faraday bags provides reliable, legal protection that works through physics rather than hoping software settings actually disable what they claim to disable. Your phone’s “location services off” setting? That’s software. Software can lie. Physics can’t.
Ready to choose a Faraday bag? See our comprehensive guides on how to choose a bag, layer construction differences, and sizing guide.