A Faraday bag for a phone is a small shielded pouch: seal the phone inside and it can't connect to cellular, Wi-Fi, Bluetooth or GPS until you take it out. Get one at least an inch longer than your phone in its case. For everyday carry, choose the Universal Signal-Blocking Pouch; for a fire-resistant fiberglass outer with room for cards, the small Fireproof Waterproof Faraday Bag.
How to Choose
Measure your phone in its case and compare it with the pouch's length, leaving at least an inch (2–3 cm) for the closure to fold or seal flat.
Also phone-sized: the small Double-Layer Fireproof Shielding Pouch, 8.3 × 4.5 in (21 × 11.5 cm), and the 12 × 20 cm (4.7 × 7.9 in) Signal Blocking Faraday Bag.
How to Check It Works
Seal the phone, close the opening fully and call it from another phone, three times. It should go straight to voicemail; a ring means the seal is open. Then try locating it with Find My or your phone's find-my-device service: it should show only its last location from before you sealed it. Turning the phone off isn't a substitute: Apple's Find My documentation says a supported iPhone can still be located for up to 24 hours after it's switched off.
Honest Notes
- It blocks only while fully sealed. A phone that's too big for the pouch keeps the closure from closing.
- A sealed phone keeps searching for a network, which uses battery. Once you take it out, it reconnects within seconds and can report its location straight away.
- It's a radio control, not a malware control. Spyware can log activity while sealed and upload it later; see what a Faraday bag blocks for phone tracking, and what it doesn't.
- Closures and seams wear with daily use. Retest every few months.
- The fiberglass pouches resist flame and splashes for a while but aren't fire-rated. The Oxford-cloth pouch isn't fire-resistant.
Questions
Do Faraday bags block 5G?
A sealed pouch with an intact lining should keep a phone off 5G as well as 4G. The shielding test in our published test pack stops at 1.5 GHz, below the mid-band frequencies much of US 5G runs on, so check yours: with 5G showing on the phone, seal it and call it.
Can I charge my phone in a Faraday bag?
Not while it's shielded. A cable through the opening leaves a gap that lets signal in. Charge the phone before you seal it, especially since a sealed phone uses battery searching for a network.
Will my alarm still go off?
Yes. Alarms, timers and anything stored on the phone keep working because they don't need a signal. The pouch just muffles the sound a little.
Is a Faraday bag the same as airplane mode?
No. Airplane mode is a software setting: GPS keeps working, and Wi-Fi and Bluetooth can be switched back on while it's enabled. A sealed bag stops the radio signals physically, and you can confirm it with a call.
Related: all Faraday bags, pouches and boxes for car keys, the full home-test checklist and what we do and don't claim.
