Best cot mattresses 2024: tested and reviewed by experts

Our expert buying advice and reviews will help you to choose a cot mattress for your baby. Keep reading to see our Best Buy recommendations that are comfortable, supportive and safe.

You need your cot mattress to be able to cope with the inevitable leaks that will happen as your baby grows, and you need it to last until your child is ready for their first bed. We've found some that are too soft, not breathable, and that won't last long enough. 

As well as our top recommendations, we share all the advice you need to help you decide which cot mattress is right for your little one. 

Take a look at our cot mattress reviews to compare all the models we've tested

The best cot mattresses 2024

Our impartial lab tests have uncovered the very best, and we’ve selected our top picks. All of them have performed well in our body support, durability and safety tests, so you can be sure you are buying a cot mattress you can rely on.

Our expert buying advice and Best Buy recommendations will help you avoid buying a cot mattress that is too soft, not durable, or lacks the permeability that will keep your baby dry and comfortable. Only logged in members can see our full list of cot mattresses in the table below. Join Which? to find out everything you need to know to make the right choice. 

Cot Mattress reviews by price

• Cot mattresses under £50
• Cot mattresses under £100
• Cot mattresses under £150
• Cot mattresses under £300

Why you can trust our cot mattress reviews 

We buy every cot mattress that we put through our rigorous tests and accept no free samples, ensuring that our reviews remain completely unbiased. Our expert lab tests measure all of the sleeping needs of an average baby, so you can be confident our top-rated models will provide a comfortable, supportive and safe sleeping surface for your little one.

We put each cot mattress through its paces in several areas, including firmness, breathability, and durability, to find the mattresses that offer the best support, have excellent air circulation to prevent overheating, and can withstand the wear and tear of everyday use. 

The best cot mattress brands

As well as our tests, we also ask parents how happy they are with their chosen brand, so we can give you some insight into the best out there along with the ones to avoid.

Our tests have uncovered a sizeable difference in the best and worst. The best-scoring brand in our tests has an average score of 79%, whereas the worst brand scores, on average, 16%. 

Have a look at the results for the biggest brands. 

Only logged-in Which? members can view the results in the table below. If you're not yet a member, join Which? to get instant access.

Avoid a cot mattress that's unsafe, is unsupportive for your baby, or lacks durability by reading our guide on what makes a Don't Buy cot mattress.

Types of cot mattress

Foam cot mattress

Pros Generally easy to keep clean, can provide good support and resistance to denting, and foam is relatively light so will be easy for you to move or turn over.

Cons Some parents don't like the idea of the basic, all-PVC-covered mattress because of concerns about clamminess, foam mattresses with ventilation holes can be harder to keep clean if your baby is sick because residue can gather in the holes and mesh, and thin foam may lose its shape and dent easily.

Generally speaking, foam cot mattresses are the least expensive type. They're usually just a piece of high-density foam with a wipe-clean, waterproof PVC cover. Some will come with two sides: a cotton side and a wipe-clean side. 

Some foam mattresses have ventilation holes, but these aren't a necessity, and you might also see hypoallergenic foam mattresses advertised. 

Spring or pocket spring cot mattress

Pros Many parents like the familiarity of a traditional spring mattress, and while the wipe-clean side is the recommended surface for your baby to sleep on, you can flip it on to the cotton side if it's hot and your baby feels clammy. 

Cons More expensive than foam mattresses with pocket spring cot mattresses being the priciest, the cotton side may be preferred for comfort, but can be more difficult to keep clean.

A simple spring mattress is made of springs secured into a rigid frame. These are then surrounded by layers of foam and fabric. 

Pocket spring mattresses are the most expensive type. These are made of coiled springs, each sewn into their own individual pocket. 

Unlike a regular spring mattress, each spring in a pocket spring mattress can move independently of the others, so the mattress is deemed to be more comfortable and give better support. These springs are, like regular spring mattresses, covered by layers of foam and fabric. 

Spring cot mattresses often have a cotton cover on one side and wipe-clean material on the other side. 

Coir or natural fibre cot mattress 

Pros One of the firmest types of mattress and they tend to last longer because they hold their shape well, so could be a sensible buy if you want to use it for more than one child. 

Cons Less widely available than foam or spring interior and can be more expensive than the alternatives.

These have a core of coconut fibre with other layers of different materials. The fibres are coated in latex for strength and protection, and the natural fibre filling helps air circulate through it. This type is available with a wipe-clean covering.

Preparing for a growing family

Our expert advice helps you make the best decisions for your loved ones

Visit our growing families hub

How much does a good cot mattress cost? 

The prices of cot mattresses range anywhere from about £35 to £250.

But price and quality don't necessarily go hand in hand, as our cheapest Best Buy costs £60, while our most expensive Don’t Buy is more than £200.

Quality and safety don't always go up with price, either, so it's worth looking at this before the price.

We award a Great Value logo to cot mattresses that are at least 20% cheaper than the average typical price for a cot mattress and score at least 60%. 

However, a Great Value cot mattress also has to be safe, so we only choose ones that get a minimum of three stars for safety and are tested to the latest version of the cot mattress safety standard (2021).

See all our Great Value cot mattresses to find an excellent low-cost option for your baby's nursery

Where to buy a cot mattress

Cot mattresses are available to buy from a range of retailers including:

• John Lewis sells own-brand mattresses that typically cost between £18 to £95 as well as other brands such as Boori, Silver Cross and Snuz.
• Argos stocks Cuggl models (the Argos own brand) which typically cost £25 to £85, as well as popular adult mattress brands such as Silent Night.
• Mamas & Papas has a wide range of own-brand models on its site costing £22 to £229, but it also stocks Snuz and Gaia.
• Smyth's Toys has a reasonable selection of cot and cot bed mattresses from the brand Baby Elegance, which cost around £25 to £80.
• Ikea sells its own branded cot mattresses in both 140 x 70cm and 120 x 60cm dimensions. Prices range from £35 to £159.

What is the standard cot mattress size in the UK?

140 x 70cm is the standard size of most UK cot beds, so you need to buy one with these dimensions. This will ensure that the mattress fits snugly into the frame, leaving no gaps around the edge.

Another typical size is 120 x 60cm. If you buy a cot that's smaller or larger than this, you can get mattresses specially made to fit, but this will cost more.

You need to make sure the mattress fits your cot or cot bed frame snugly. A gap bigger than 3cm (1.2in) is a potential hazard for your baby as their arms, legs or head could get trapped in the gap.

Not all mattresses come in the same standard size, but your cot or cot bed should specify which size it requires. 

We recommend that your baby's cot mattress is at least 10cm thick. Your baby’s weight will be concentrated on a small area of the mattress, and you don't want their body sagging through and hitting the base underneath.

Best cot bed brands and expert buying advice: we've quizzed parents on big-name brands, including Ikea, John Lewis and Mamas & Papas, to uncover the most popular 

Cot mattress safety

Babies need to sleep on a mattress that's firm and flat with a waterproof cover to help keep it clean and dry. You can assess the firmness and flatness by pressing your hand firmly on the centre and edges. There should be some resistance and it should bounce back immediately.

In our cot mattress tests, we assess the support it will provide for your baby. Our experts measure body support before putting it through a durability test that simulates two to three years of regular use.

We then measure the body support after these tests to see how the mattress will hold up, so you know it's going to still be doing a great job of keeping your baby comfortable over time. 

Many mattresses (mainly of the spring and pocket spring varieties) are made to be reversible. Each side of the mattress will be specially designed to accommodate the needs of your rapidly growing baby.

That's because a cot bed mattress might be used for five or six years, during which time your baby will more than triple in weight. Because of this, manufacturers often design cot bed mattresses with one side specifically for babies and the other for toddlers or children.

Typically, one side will have springs and foam designed to be sturdy, but gentle for a baby to sleep on for the first 12 months. The reverse side will have sturdier material to cope with a growing toddler.

The mattress should clearly indicate which side is suitable for what age group. 

Cot mattress and bedding safety – read our expert advice on setting up a safe sleeping environment for your child

Can I use a second-hand cot mattress for my baby?

We generally don't recommend you buy or use a second-hand cot mattress. The Lullaby Trust (the safer sleep charity) states there is some research that has found an increased chance of sudden infant death syndrome (SIDS) when using a second-hand mattress brought in from outside of the family home, although the link is not yet proven.

If you're using a second-hand cot mattress, inspect it before your baby starts using it, ensuring that it's in good condition, with no rips or tears. The mattress should still be firm and springy when you push your hand down on it, and there should be no dips or indentations.

Ideally, the mattress will have a removable cover, which can be washed at 60°C to remove any bacteria.

How should you dispose of your cot bed mattress?

We don't recommend buying a second-hand cot mattress. Which? tests have demonstrated that mattresses can lose up to a quarter of their firmness in just a few years of use, so it's best to get rid of the mattress once your baby is no longer using it.

Much like a full-size mattress, they're not always the easiest to dispose of, as they won't be picked up by your general council rubbish collection. Luckily, as they're smaller, they tend to fit in a car more easily so you should be able to take the cot mattress down to your local tip.

Some cot mattress brands, such as Kub, offer a mattress collection and recycling scheme, but this is a rare occurrence for cot mattress manufacturers. It's also possible to organise a mattress collection from a professional recycling firm, but you'll have to pay for this service.

Alternatively, if you're particularly creative and can create a frame to go round it, you could try converting your baby's cot mattress into a dog bed (best for larger dogs).

Want to know how we put each mattress through its paces? Learn more about how we test cot mattresses