Master Lock Magnetic Key Holder
4.5Editor score
Fits 1 to 2 keys
Durable plastic construction
Sliding cover design
In this guide
Finding a secure place to hide a spare key is essential for vehicle owners who want to avoid lockouts. A magnetic key box for under car offers a discreet and accessible solution for storing emergency keys safely.
We evaluated ten popular models based on magnet strength, weather resistance, interior capacity, and ease of use. Each product was assessed for its ability to hold keys securely while remaining hidden from plain view.
Every pick includes detailed specs and honest pros and cons to help you choose the right fit. Prices and availability may change, so verify current details before purchasing to ensure the best value.
Top 3 Picks for Best Magnetic Key Box for under Car
Magnetic Key Box for Under Car
4.6Editor score
Super strong magnet hold
Waterproof hidden design
Portable and secure
Hide a Key Outside with our Grey Magnetic Box
4.6Editor score
Air-tight waterproof seal
Gorilla Box durability
Strong neodymium magnets
Top 10 Best Magnetic Key Box for under Car in 2026 Compared
The following table provides a side-by-side comparison of all ten models evaluated in this guide. Each entry highlights key specifications to help you quickly identify the right storage solution for your needs.
ProductsSpecificationsEditor scorePrice
Editor's Choice
Magnetic Key Box MM1 Regular
Waterproof hidden design
Portable and secure
Super strong magnet hold
Undercarriage placement
4.6Editor score
Editor's Choice
2 Hide A Key Magnetic Under Car
Jumbo size capacity
Tough ABS case
Multi-use storage
Two premium magnets
4.6Editor score
Best Premium
Large Magnetic Key Box
Fits bulky key fobs
IPX5 weather protection
Four-magnet mounting
Dual retention latches
4.3Editor score
Master Lock Magnetic Key Holder
Fits 1 to 2 keys
Durable plastic material
Sliding cover design
Steel surface attach
4.5Editor score
Magnetic Key Box with Combination Lock
Resettable security code
Five strong magnets
Anti-drop magnetic holder
Includes waterproof bags
4.2Editor score
Magnetic Key Holder Under Car
Splash resistant design
Two neodymium magnets
Large storage capacity
Removable padding inside
4.7Editor score
Upgraded Magnetic Key Holder
Safety buckle design
Super strong magnetic
Large storage space
Reliable material use
4.6Editor score
Nite Ize Hideout Magnetic Key Box
Waterproof IPX7 rating
Versatile key storage
Secure magnetic box
Extra large size
4.6Editor score
Magnetic Key Box with 3 Magnets
Super strong triple magnet
Waterproof weatherproof
Rugged durable build
Easy to install
4.6Editor score
Hide a Key Outside Grey Box
Reliable durable design
Strong magnetic hold
Undercarriage placement
Convenient and secure
4.6Editor score
1. Magnetic Key Box MM1 Regular – Best Overall Hidden Storage
Magnetic Key Box MM1 Regular
Waterproof hidden design
Portable and secure
Super strong magnet hold
Undercarriage placement
This magnetic key box offers a reliable solution for hiding spare keys under your vehicle. It features a waterproof design and strong magnets to keep keys safe from elements and theft.
Pros
- Compact and easy to hide
- Strong magnet keeps it secure
- Waterproof material protects keys
- Affordable price point
- Simple slide open mechanism
Cons
- Small interior limits bulk fobs
- May need extra zip ties
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The super strong magnetic hold ensures the box stays attached to your car frame even on rough roads. Its portable size makes it easy to conceal in various spots without interfering with driving.
While compact, the interior might not fit bulky key fobs or multiple items. Adding a zip tie provides extra security if you are concerned about high-speed travel or theft.
Ideal for daily drivers needing a quick emergency key access, this box balances price and performance well. It is a solid choice for anyone wanting discreet and secure key storage.
Waterproof Protection
The waterproof design ensures your keys stay dry even in heavy rain or snow conditions.
Strong Magnet
Powerful magnets keep the box firmly attached to any ferrous metal surface under the vehicle.
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2. 2 Hide A Key Magnetic Under Car – Large ABS Case Option
2 Hide A Key Magnetic Under Car
Jumbo size capacity
Tough ABS case
Multi-use storage
Two premium magnets
This option stands out with a jumbo size ABS case that fits more than just keys. It is designed for multi-use storage including small valuables and notes.
Pros
- Large ABS case fits more
- Two premium magnets for hold
- Multi-use for valuables
- Tough weather-resistant material
- Easy slide open access
Cons
- Size might be noticeable
- Instructions reference video only
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The two premium magnets provide a secure hold on steel surfaces, ensuring the box stays put. The tough ABS case protects contents from outdoor weather effectively.
Its larger size might be easier to spot compared to slimmer models, so placement matters. Relying on video instructions for setup might be tricky without internet access.
Best for those needing extra space for cash or trackers, this box offers versatility. It is a practical choice for RV owners or families needing hidden storage.
Multi-Use Storage
The case is not only for keys but also holds money, notes, and tracking devices safely.
Jumbo Size
Pre-measured dimensions ensure you know exactly what fits inside before purchasing.
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3. Large Magnetic Key Box – Fits Bulky Key Fobs
Large Magnetic Key Box
Fits bulky key fobs
IPX5 weather protection
Four-magnet mounting
Dual retention latches
Designed for modern vehicles, this box is spacious enough to fit bulky key fobs and multiple keys. It offers a large capacity for other essentials like cards or trackers.
Pros
- Holds bulky key fobs easily
- Four magnets distribute force
- IPX5 weather protection
- Dual retention system
- Large capacity for essentials
Cons
- Not a combination lock
- Avoid heat moving parts
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Four magnets distribute the holding force across the surface for a stable mount. The IPX5 rating helps protect against rain and road spray effectively.
The box does not block signals or lock combinations, which might be a downside for some. Avoid placing near moving parts to prevent damage during driving.
Ideal for fleet vehicles or trucks with large fobs, this box offers reliable storage. The dual retention system adds extra security for peace of mind.
Bulk Fob Friendly
The housing dimensions allow modern car key fobs to fit without forcing the lid.
Mounting Options
Four side latches and holes for zip ties ensure the box stays secure during travel.
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4. Master Lock Magnetic Key Holder – Trusted Brand Value
Master Lock Magnetic Key Holder
Fits 1 to 2 keys
Durable plastic material
Sliding cover design
Steel surface attach
Master Lock is a known name in security, offering this budget-friendly magnetic key holder. It features a durable plastic build and a convenient sliding cover for access.
Pros
- Very affordable price
- Trusted brand reliability
- Sliding cover design
- Fits 1 to 2 keys
- Durable plastic construction
Cons
- Not for car use
- Limited interior volume
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The box securely attaches to any steel surface, making it versatile for use around a home or garage. It comfortably stores 1 to 2 keys for emergency use.
Though designed for general steel surfaces, some may find the interior volume limited for larger fobs. Always check placement instructions to avoid using directly under cars if not recommended.
For homeowners needing a simple spare key hideaway, this box is a great start. Its low price point makes it an accessible choice for basic security needs.
Brand Reliability
Master Lock is a trusted name in security, ensuring quality and durability in this unit.
Sliding Cover
The built-in stop prevents the cover from being dropped or misplaced during use.
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5. Magnetic Key Box with Combination Lock – Secure Code Option
Magnetic Key Box with Combination Lock
Resettable security code
Five strong magnets
Anti-drop magnetic holder
Includes waterproof bags
This model adds a resettable combination lock for an extra layer of security. The five strong magnets ensure a firm grip on the vehicle chassis.
Pros
- Resettable combination lock
- Five strong magnets for hold
- Anti-drop magnetic holder
- Includes waterproof bags
- Durable material build
Cons
- Slightly heavier than others
- Code management required
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The anti-drop design and waterproof bags protect your items from moisture and impact. It is made of ultra-durable material for long-term use under the car.
Managing a combination might be a hassle if forgotten, adding complexity to access. The extra bulk compared to simple boxes might affect hiding spots.
Best for those who prioritize code security, this box offers double insurance for your keys. It is a solid choice for high-value vehicles requiring more protection.
Combo Lock
The 4-digit password can be reset to make the hidden key safer from strangers.
Extra Protection
Includes waterproof bags to reduce friction and protect items inside the box.
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6. Magnetic Key Holder Under Car – Splash Resistant Option
Magnetic Key Holder Under Car
Splash resistant design
Two neodymium magnets
Large storage capacity
Removable padding inside
With a high rating, this box is known for its splash-resistant design and reliable hold. It features two strong neodymium magnets to keep the box in place.
Pros
- Highly rated performance
- Splash resistant design
- Two neodymium magnets
- Large storage capacity
- Removable padding inside
Cons
- Fob protection recommended
- Latches need care
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The large capacity allows for multiple keys and valuables like AirTags. Removable padding lets you adjust space based on what you need to store.
For heavy rain or puddles, using a zippy bag is suggested for fobs to prevent water entry. The latches are strong but need careful handling to avoid breaking.
A great pick for drivers wanting flexibility and high user satisfaction, this box works well. It balances capacity with weather resistance for everyday use.
Splash Resistant
The self-aligning retainer ensures the box stays closed unless intentionally opened by you.
Removable Padding
Padding reduces shaking and rattle but can be removed for more storage space.
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7. Upgraded Magnetic Key Holder – Thick Sturdy Build
Upgraded Magnetic Key Holder
Safety buckle design
Super strong magnetic
Large storage space
Reliable material use
This upgraded model features thicker material for sturdier durability than many competitors. It includes a safety buckle design to prevent accidental release during travel.
Pros
- Thicker sturdy material
- Safety buckle design
- Super strong magnetic
- Large storage space
- Waterproof and weatherproof
Cons
- Padding may reduce space
- Heavier than standard boxes
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Equipped with three neodymium magnets, it provides a robust hold on steel surfaces. The soft cushion inside protects keys from damage while in transit.
The padding might reduce interior capacity for larger items, but it can be removed. It is heavier than standard models, which could affect placement options.
Ideal for owners seeking maximum durability and protection, this box offers peace of mind. It is perfect for harsh environments or long-distance travel needs.
Safety Buckle
Buckles are designed to endure repeated bending without detaching unexpectedly.
Material Quality
Thoroughly tested in all environments including snow, rain, and mud.
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8. Nite Ize Hideout Magnetic Key Box – IPX7 Waterproof
Nite Ize Hideout Magnetic Key Box
Waterproof IPX7 rating
Versatile key storage
Secure magnetic box
Extra large size
Nite Ize offers a waterproof box with an IPX7 rating for high water resistance. The extra large size allows for more contents including bulkier items.
Pros
- IPX7 waterproof rating
- Extra large size
- Secure magnetic box
- Versatile key storage
- Worry free guarantee
Cons
- Extra large might hide less
- Price higher than basic
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Powerful neodymium magnets secure the box to any metal surface effectively. It comes with an adhesive-backed metal plate for attaching to non-metal surfaces.
Its size might make it harder to hide discreetly under a car. The price is higher than basic models but reflects the quality and guarantee.
Best for outdoor enthusiasts needing maximum water protection, this box is excellent. It is versatile for use on boats, sheds, and other gear.
Waterproof
Designed to keep contents safe and dry even in heavy water exposure.
Worry Free
Nite Ize backs this product with a Worry Free Guarantee for peace of mind.
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9. Magnetic Key Box with 3 Magnets – Triple Hold System
Magnetic Key Box with 3 Magnets
Super strong triple magnet
Waterproof weatherproof
Rugged durable build
Easy to install
This box features a triple magnet system for a maximum-strength hold on ferrous surfaces. It is made from great ABS plastic for rugged durability in harsh conditions.
Pros
- Triple magnet system
- Waterproof weatherproof
- Rugged durable build
- Easy to install
- Compact design
Cons
- Installation needs clean surface
- May not fit all fobs
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Its compact design ensures it won't interfere with driving or become an eyesore. Installation is simple with no tools required, making it user-friendly.
You may need a clean metal surface for the magnets to work best. Not all bulky fobs may fit due to its compact size.
Ideal for trucks and SUVs needing a discreet and strong hold, this box is reliable. It is a perfect gift for outdoor enthusiasts or car owners.
Triple Magnet
Three powerful magnets ensure your spare key never falls off even on rough roads.
Easy Install
Simply close the lid and attach the box to any clean metal surface.
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10. Hide a Key Outside Grey Box – Premium Air-Tight Seal
Hide a Key Outside Grey Box
Reliable durable design
Strong magnetic hold
Undercarriage placement
Convenient and secure
Known as the Gorilla Box, this model offers a premium air-tight magnetic seal. It stays secure with two strong neodymium magnets attached to your car.
Pros
- Air-tight waterproof seal
- Strong neodymium magnets
- Reliable and durable
- Convenient access
- Gorilla Box quality
Cons
- Higher price point
- Grey may contrast with dark cars
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The undercarriage placement ensures discreet hiding of your keys for added security. It is built to be reliable and durable for long-term use.
The higher price point may be a consideration for budget-conscious shoppers. The grey color might be more visible than black on dark vehicles.
Best for those prioritizing a premium seal and brand reputation, this box excels. It provides peace of mind for secure and accessible key storage.
Air-Tight
The air-tight design protects your keys from moisture and corrosion effectively.
Gorilla Box
This box offers a durable solution for hiding keys with reliable access.
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Buying Guide – How to Choose the Best Magnetic Key Box for under Car
Selecting the right magnetic key box involves evaluating several factors to ensure your keys stay safe and accessible. This guide breaks down the key aspects to consider before you buy.
Magnet Strength
The strength of the magnets determines how securely the box will stay attached to your vehicle. Look for models with multiple neodymium magnets or high pound-force ratings to ensure the box does not fall off during high-speed driving or on rough terrain. Weak magnets may allow the box to detach and get lost.
Prioritize boxes with at least three to five strong magnets for reliable holding power under the chassis.
Weather Resistance
Since the box will be exposed to the elements, weather resistance is critical to protect your keys from rust and water damage. Look for waterproof ratings like IPX5 or IPX7 to ensure the interior stays dry during rain, snow, or road spray. Some models use air-tight seals for added protection against moisture.
Always check the sealing quality to ensure your keys remain functional in extreme weather conditions.
Capacity and Size
The interior size of the box should match what you plan to store, such as standard keys, bulky fobs, or trackers. Measure the interior dimensions to ensure it fits your specific key type. Larger boxes may hold more items but could be easier to spot from outside.
Choose a size that balances storage needs with discretion for better security.
Security Features
Some models include combination locks or extra retention methods like zip tie holes to add a layer of security against tampering. While basic magnetic boxes rely on stealth, a lock adds an additional barrier for valuable items. Consider if you need this extra protection based on your security concerns.
Locks provide peace of mind but add complexity to access your keys quickly in emergencies.
Durability of Materials
The materials used for the box and hinges must be tough enough to withstand vibration, impact, and UV exposure over time. ABS plastic and reinforced latches are common indicators of durability. Avoid cheap plastics that may crack under stress or temperature changes.
Opt for rugged materials that are specifically tested for automotive undercarriage use.
Installation Ease
A good magnetic key box should be easy to install without tools. Check if the product includes instructions or video guides to help you place it correctly. Some boxes require a clean metal surface for magnets to work effectively, so consider how easy it is to prep the area.
Simple installation ensures you can hide your keys quickly without hassle.
Price and Value
Prices vary widely based on features like locks, size, and brand reputation. While budget options may save money, premium models often offer better durability and weather protection. Determine your budget but prioritize essential features like magnet strength and waterproofing over minor cost savings.
Invest in a box that offers reliable performance within your price range.
Brand Reputation
Well-known brands often provide better customer support and warranties for their products. Check reviews to see how the brand handles issues or defects. A reputable brand might also have better quality control, resulting in a more consistent product.
Consider established brands for added assurance of product quality and reliability.
How to Use and Care for Your Magnetic Key Box for under Car
To use your magnetic key box, place your spare keys inside the compartment and close the lid securely. Ensure any locks or latches are engaged before attaching the box to your vehicle to prevent accidental opening.
Attach the box to a clean, flat steel surface under the chassis or frame using the built-in magnets. If possible, add zip ties through the provided holes for extra retention during rough driving conditions.
Regularly inspect the box for signs of wear, corrosion, or magnet weakening. Clean the exterior with a damp cloth to remove dirt and grime that could interfere with the seal or magnets.
Frequently Asked Questions
Are magnetic key boxes safe for cars?
Yes, most high-quality magnetic key boxes are safe for cars if they use strong neodymium magnets and are placed on clean, flat steel surfaces. However, avoid mounting near moving parts or hot components to prevent damage.
Will rain damage the keys inside?
If you use a waterproof or water-resistant box with a proper seal, rain will not damage the keys. Models with IPX ratings or air-tight designs are recommended for wet conditions to keep the keys dry and functional.
How strong do the magnets need to be?
Magnets should have a holding force of at least 50 pounds to ensure the box stays on the car frame. Multiple magnets distributed across the box are better than a single magnet for stability.
Can I store a key fob in these boxes?
It depends on the size of the box. Many models fit standard keys, but bulky key fobs may require a larger capacity box. Check the interior dimensions before purchasing to ensure a fit.
Do I need tools to install them?
Most magnetic key boxes require no tools for installation. You simply place the keys inside, close the box, and attach it to the metal surface. Some may use zip ties for extra security.
How often should I check the box?
It is recommended to inspect the box every few months to ensure the magnets are strong and the seal is intact. Regular checks prevent failure when you actually need to retrieve your keys.
Final Thoughts on Choosing the Best Magnetic Key Box for under Car
Choosing the right magnetic key box for under car involves balancing security, durability, and convenience. The top picks include the MM1 Regular for value, the Large Magnetic Key Box for capacity, and the Gorilla Box for premium weather protection.
Prioritize magnet strength and waterproof ratings to ensure your keys stay safe in all conditions. Adding zip ties for extra retention is a smart move for frequent drivers.
Remember to verify current prices and availability before buying. A reliable key box can save you from expensive lockouts and provide peace of mind on the road.