The Best Car Key Signal Blocker 2022

Keyless car crime is a huge problem in the UK and it’s on the rise. However, by using one of the many car key signal blockers on the market, you can make the criminal’s life much harder and block the signal they require for using their relay attack devices.

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Best Car Key Signal Blocker
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If you are looking for a quick answer, the best car key signal blocker is the MONOJOY Bag, which features a new and improved design that’s made from PU leather. It’s suitable for all key fob sizes and it effectively blocks all signals from leaving the faraday bag. If you would prefer to use a faraday box, the Todoxi Box is the best alternative for multiple keys.

To rate the car key signal blockers within this article, we carried out plenty of testing (as shown in the image above), hours of research and considered multiple factors. The factors that we took into consideration included their size, ease of putting your key into the bag or box, design, warranty and value for money.

Car Key Signal Blocker Comparison

Car Key Signal BlockerTypeSize
MONOJOY CagePouch14.0 x 10.0 cm
Defender Blocking CasePouch18.5 X 11.5 cm
Blockr Anti TheftMetal Pot6.4 x 10.5 cm
Todoxi BoxBox13.8 x 10.8 cm
OCOOPA BoxBox16.0 x 12.0 cm
MONOJOY Key CaseKey Ring9.5 x 5.5 cm

Due to the new wave of keyless car crime, many car owners are having to find additional ways to protect their pride and joy against tech-savvy criminals. As shown in the table above, there are many types of car key signal blockers available and they all aim to block any signals passing outside of the pouch, pot, box or key ring.

Below is a list of the best car key signal blockers that block all key fob signals and are convenient to use.

The Best Car Key Signal Blocker

1. MONOJOY Faraday Bag for Car Keys

By far the most popular car key signal blocker is the MONOJOY Faraday Bag, which features a new and improved design. It’s constructed of a high quality PU leather and is designed to hold every type of key fob available in the UK.

Along with blocking key fob signals, it’s also able to block calls, SMS, Wi-Fi, 4G, Bluetooth, RFID, NFC and much more.

Other features of the MONOJOY Faraday Bag include:

  • High quality leather pouch design
  • 14 x 10 cm in size
  • Supplied with two bags
  • Blocks a wide range of other signals
  • Available in alternative designs
  • Tried and tested in the UK

The MONOJOY Faraday Bag is an excellent all-round option that ticks all the boxes and is convenient to use. It also comes in a twin pack for extra bang for your buck, which you can use to protect your spare keys.
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2. Defender Signal Blocking Pouch

Defender Blocking Case
Another similar car key signal blocker is the Defender Pouch, which is available in black, pink or grey. In terms of the design, it’s compatible for storing all smartphones, credit cards and a wide range of key fobs.

According to the brand, their car key signal blocker is designed and manufactured using the latest specialist RPF material for maximum safety. It also meets the “Secured By Design Police Preferred Specification”.

Other features of the Defender Signal Blocking Pouch include:

  • High quality and durable construction
  • Available in a single or twin pack
  • Black, grey or pink designs
  • Police Preferred specification
  • 18.5 X 11.5 cm in size

The Defender car key signal blocker is an affordable yet high quality faraday pouch that won’t disappoint. It also features a “Police Preferred” design that’s tried and tested for complete peace of mind.
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3. Blockr Keyless Car Key Signal Blocker Pot

Blockr Anti Theft
Another popular design is the convenient and extra secure alloy metal pot by the Blockr brand. It’s suitable for storing one or two key fobs and comes with a lifetime warranty for complete peace of mind.

In order to increase the protection against relay crime, it features three different types of protection. This includes the standard faraday lining, a scanner resistant alloy construction and a seamless secure lid to prevent signal leakage.

Other features of the Blockr Signal Blocker Pot include:

  • Triple keyless fob protection
  • Scanner resistant alloy construction
  • Full support and warranty
  • 6.4 x 10.5 x 5.0 cm in size
  • Brushed metallic finish

The Blockr Signal Blocker Pot is one of the most secure options within the article but also the most expensive. However, it does come with an impressive warranty and is ideal for key fobs with multiple key rings attached.
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4. Todoxi Car Key Signal Blocker Box

Todoxi Box
Rather than having multiple faraday pouches, a car key signal blocker box is a better option for storing multiple keys. The Todoxi Faraday Box is a great option that can hold up to 7 sets of keys, which makes it far more cost effective solution when compared to using multiple pouches. In terms of the construction, it’s covered in an anti-friction leather with a high density faraday internal fabric.

Other features of the Todoxi Signal Blocking Box include:

  • Blocks 100% of all signals
  • 13.8 x 10.8 x 7.0 cm in size
  • Holds up to 7 key fobs
  • Provides more than 3 years of service
  • Stylish design

If there are multiple cars at your household, choosing a faraday box that can hold multiple keys is the best option. The Todoxi is a high quality yet affordable option that offers more than 3 years of service life and a stylish design.
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5. OCOOPA Faraday Key Signal Blocker Box

Another stylish faraday box is by the OCOOPA brand and they offer it in either a black or brown design. It’s one of the largest within this article and it can also be used to store other valuables such as watches, credit cards and much more.

Other features of the OCOOPA Faraday Box include:

  • Block car key and mobile phone signals
  • 16 x 12 x 8.9 cm in size
  • Imported wood material
  • Insulating cloth lining
  • Premium leather in either black or brown
  • Double locks

Although more expensive than the Todoxi alternative above, it’s larger in size and has an additional lock for peace of mind. It also has a brown design, which may be desirable for those wanting to match it with the decor of their home.
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6. MONOJOY Faraday Key Ring for Car Keys

Another car key signal blocker by the popular MONOJOY brand is their key ring box alternative. It’s designed to be compatible with 99% of key fobs and is available in a carbon fibre, blue or a solid black design.

Other features of the MONOJOY Faraday Key Ring include:

  • 9.5 x 5.5 x 4.0 cm in size
  • Blocks all signals and protects the key fob
  • Available in three styles
  • Premium RF shielding material
  • Durable hook design

Overall, it’s a compact and convenient method of storing your key fob and it can also be taken with you wherever you go. The only main drawback is that it does come with a premium price tag when compared to the standard faraday pouch.
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How We Tested & Rated The Car Key Signal Blockers

Over the last few years, many brands have started to release various faraday bags and other car key signal blockers. However, to help you choose the best, we have carried out plenty of testing and research and also considered a number of factors. The factors that we considered included the size, ease of putting your key into the bag or box, design, warranty and value for money.

As shown in photo, faraday bags are designed to be larger than the key but there are alternatives that come in the form of a box that can be used for multiple keys.

faraday bag for car keys

In terms of our testing, we have tried various options from top rated brands in the UK and also used a range of different keys. Below is a video of us testing one of the car key signal blockers that we posted upon our Instagram page.

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As you can see from the video, the key can’t transmit a signal outside of the faraday bag for unlocking the door. It’s really that simple and it’s the reason why they are very popular for protecting your car against keyless entry theft.


Unfortunately, car theft and in particular, relay crime isn’t going to go away anytime soon. Therefore, investing into a car key signal blocker for all your key fobs is highly recommended. You can even purchase an old-fashioned steering wheel lock for additional security.

All of our recommendations are suited to a range of budgets and include all the different types of signal blockers on the market. Regardless of the car key signal blocker you buy, it’s best to be safe than sorry.

YourCar Author Dan

Written By Dan

Dan has been a car enthusiast ever since he can remember and has an extensive range of cars that include classic cars that he has restored himself from a barn find condition to modern performance cars. Whether you need advice on how to install car parts or recommendations on what products to buy, Dan’s first-hand experience will certainly help.

If you want to find out more about Dan, our testing process or the website itself, visit our about page for further information.

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