There are countless reasons to invest in a key safe, from the peace of mind of knowing your spare key is secure to giving access to authorised people such as tradespeople or Airbnb guests.

The best key safes are a far better solution than stashing a key under a mat or hooking it in the shed.

Key safes have become common around the country, especially in tourist destinations, where mounting one of these simple boxes next to the door is an easy way for guests to gain access without having to work out complex handover instructions.

Read more: Best video doorbells, tested by a smart home tech expert

However, as I found out while testing, not all key safes are built the same; while the basic function is the same, some features, pricing, and durability differ greatly.

In this test, I’ve looked at a range of simple coded key safes that use a four-digit combination lock to gain access. These range from inexpensive combination boxes to Police Preferred models.

A key safe is a simple box you attach to the outside of your property. In all cases, the products in this review require light DIY skills to install. Once in place, a combination lock lets you access the small, key-sized inner chamber, where you can store keys securely until you need them. You can then give others who need access to your home the code to the key safe, avoiding the need to pop a key under the mat.

In this review, I tested a wide variety of key safes, from straightforward four-digit combination boxes you often see mounted beside doors to the Police Preferred requirements. I tested each key safe for the installation process, ease of use, and capacity.

Once the keys were installed, I checked how easy the combination dials or buttons were to operate and how easy it was to gain access. This test was carried out in both daylight and night conditions. I also subjected each keysafe to two break-in attempts: the first used a screwdriver to try to lever the front of the safe open, and the second was a simple impact test to see if the safe would break or shatter when hit with a hammer.

What we love: Ultra-secure, backlit keys, with internal key hooks

The Ark Tamo uses a clever multi-push concept, letting you press individual buttons up to four times and creating more than 9.7 million possible combinations.

Installation is via four mounting points through the backplate, with a set of security screws supplied. There are 10 large buttons surrounding the central release mechanism, with illumination making the controls easy to see even in the dark. I also found the large buttons easy to operate with cold and wet hands.

Setting the combination is less straightforward – read the instructions very carefully – but once inside, there’s enough space for five flat keys or three bulkier tubular keys. The exterior weather cover is also appreciated.

The key safe box stood up well to break-in attempts. A screwdriver failed to break through, while repeated hammer blows didn’t crack through the casing.

• Lock type: Mechanical multi-push keypad
• Secured by Design Police Preferred; LPCB LPS 1175 Issue 8 A10

Budget key storage safe

What we love: Small, surprisingly spacious, and impressive durability

Master Lock’s Select Access 5401EURD is a compact, wall-mounted box secured by four rotating combination wheels.

Installation is simple, with four light-duty screws that are supplied alongside the instructions (I would upgrade these for a little more durability). To set your combination, slide a small reset lever inside the compartment, rotate the four dials, and return the lever to its original position.

The dials can be small and fiddly – particularly with cold hands – and there’s no illumination. The internal cavity leaves ample space for one or two keys – but there’s room for eight keys with careful arrangement.

Weather protection is basic, so I’d suggest positioning it in a relatively sheltered place. Attempting to break in with both a screwdriver and a hammer proved impossible; however, there are no independently verified security credentials for this safe.

For large bunches of keys

What we love: Substantial casing, encased weather protection, and large internal cavity

The Burton Keyguard Digital XL uses a mechanical push-button lock. Among the largest key safes I tested, the box includes everything required for installation, including four hefty screws.

The full-protection weather cover is as substantial as the safe itself – it completely stopped water from reaching the safe. Each button has a contrasting green number that makes it easy to identify in low light.

Setting the combination is easy, with codes of between three and eight characters. While the internal hook only takes two flat keys, it’s the largest compartment I tested, with space for a substantial bunch of keys.

It proved impressively resistant to forced entry. The Keyguard Digital XL isn’t the most discreet option, but it still isn’t huge and feels solid and secure.

• Lock type: Mechanical push button

What we love: Easy to install and use, relatively affordable, and robust build quality

The C500 Pro is one of the more established high-security key safes, and for good reason. The company supplies four security screws, and access is through a conventional push-button keypad.

The buttons are small but easy to locate even in low light; however, there's no backlit illumination.

Setup is exceptionally straightforward, with more than 4,000 possible combinations (each button can appear only once in a combination). The space inside features a single hook, but can easily accommodate up to seven flat keys.

Its removable weather cover completely shields the keypad, and I was also impressed by the hardened zinc-alloy construction. To finish the test, I tried several firm hammer blows; while that caused some cosmetic damage, the case held.

• Lock type: Mechanical push button
• Secured by Design Police Preferred; LPCB certified

Maximum security key safe

What we love: Reinforced internal construction, independently security tested, and excellent all-weather usability

This heavyweight keysafe is a serious security device. The casing is made from zinc alloy: it conceals a stainless-steel internal vault, with hardened anti-saw pins and coned hinge pins for further protection.

Installation is aided by two sets of security screws for different mounting situations, with four fixing points through the backplate. The keysafe can be accessed via the 10 illuminated buttons, which are easy to use with cold, wet hands. Inside, two hooks provide space for around five flat keys each, or two to three bulkier tubular keys.

Setting the combination proved less intuitive, but Ark’s online video instructions make the process considerably clearer. There's little doubt this key safe is robust, weighing more than 2.2 kg with ample weather protection.

Both the screwdriver and hammer test failed; there were visible marks, but the safe remained intact.

This is an expensive option and setting the initial code could be simpler, but its combination of excellent all-weather usability, substantial construction and independently certified security made the Tamo Pro a great security-focused option.

• Lock type: Mechanical push button
• Secured by Design Police Preferred; LPCB LPS 1175 Issue 8 A10 & B1

Key safe for accessibility

What we love: One-handed operation, tactile push buttons, and simple setup

The P500 Pro’s large push-button controls and rotary release make it easy to operate with one hand, or for anyone with limited dexterity.

Inside the box is everything you need for installation, including four substantial screws to secure the safe to a suitable wall.

The safe’s design and operation are easy. As with the C500 Pro, you can use each number only once, but the order you press them in doesn't matter. A code set as 1-2-3-4 will also open with 2-3-1-4.

The buttons feature raised numbers for touch. However, there’s no illumination and the dark finish makes the numbers difficult to identify even in shaded areas.

A flip-down weather cover protects the entire control area and performed very well in my water test. Build quality is ultra-robust, and attempts to lever it open proved unsuccessful. A hammer similarly failed to break through the casing or gain access.

• Lock type: Mechanical push button
• Secured by Design Police Preferred; LPCB certified

Compact key safe storage

What we love Inexpensive, simple four-dial operation, and robust zinc-alloy casing

The AJ Products Key Hider is a simple, inexpensive option that combines a conventional four-dial combination lock with a tough zinc-alloy casing.

Complete with everything you need for installation, setting the safe combination is quick and considerably easier than programming some of the more sophisticated push-button models.

Weather protection is fairly basic, with a sliding cover shielding the combination wheels. The small dials also became harder to rotate with cold hands, and there's no illumination.

The safe is relatively compact, but it proved considerably tougher than expected in testing. During the impact test, the only weakness was the supplied fixings, which gave way.

As with the other smaller safes, installation is particularly important. I’d upgrade the supplied fixings and position it a little more discreetly, and in a sheltered location.