Best humidifiers 2024: Which? Best Buys and expert buying advice

Humidifiers are designed to add moisture to the air and prevent dryness that could cause irritation in parts of the body, such as the skin, nose or throat.

A good humidifier will add enough moisture to the air to create a comfortable environment and do so in a quiet and energy-efficient way. But buy the wrong one and it could be fiddly to fill, make noisy dripping sounds or just not be very effective at humidifying the air.

Find out our top picks of the best humidifiers in the table below, or read our humidifier reviews to compare all lab-tested humidifiers, and avoid overspending or ending up with a humidifier that's not suited to your needs.

Best humidifiers for 2024

Table last updated April 2024.

What should the humidity be in your house and how is it measured?

Experts generally agree that you should aim for a humidity level of 30-50%. This is measured as relative humidity (RH), that is, the water vapour content in the air expressed as a percentage of the amount of water needed to achieve saturation at the same temperature. A reading of 100% RH means the air is totally saturated and wouldn’t be able to hold any more. 

If you increase the temperature, the amount of water vapour the air can hold increases, so the RH decreases. This is what can happen during the winter when people put their heating on, and it can lead to dryer environments.

If the RH is above the target of around 30-50%, you may start to feel uncomfortable. You may feel sweaty, clammy and complain that the weather is very muggy.

What type of humidifier should you buy?

While there are different types of humidifiers, it can be confusing as they can often go by different names depending on the type of technology used to release vapour into the air. However, generally, you can divide them into two types – cool mist and warm mist.

Cool mist humidifiers

As the name suggests, these don’t use any form of heat to create the mist that’s released into the air. 

Ultrasonic humidifiers produce a mist via ultrasonic vibrations. They use a metal or ceramic ‘diaphragm’, which vibrates at an extremely high frequency against water, creating droplets that are blown out into the room as a fine mist.

Evaporative humidifiers work via a filter material, a bit like a wick, that dips into the water, absorbing droplets. The humidifier fan then blows through the material and this releases water vapour into the air. 

The difference between an evaporative and ultrasonic model is that these release vapour, whereas the ultrasonic releases tiny water droplets. Evaporative humidifiers tend to have less of an issue with depositing fine minerals that might be present in the water, because they’re filtered out during the evaporation process.

Cool mist humidifiers can be a good option to use with babies, children and pets, as there’s less risk of them being exposed to hot steam, which could be dangerous. Even so, you should keep humidifier devices out of reach of pets and children where possible.

Warm mist humidifiers

Sometimes known as a steam vaporiser, a warm mist humidifier uses heat to create water vapour. They tend to create quite a bit of steam, and often use more energy because of the heating element.

The action of heating the water means there’s less risk of the water containing any biological nasties such as bacteria or mould.

Does a humidifier help with a cough?

A humidifier may be able to help with a cough. This is because when you breathe in more humid air, it helps to moisten the airways in your lungs, which, if you have a dry or tickly cough, could make it more productive.

It may also help with the following:

Reducing snoring – if you or your partner snore and the air is dry, this may make snoring worse as the airways aren’t sufficiently lubricated. Adding moisture to the air may help. 

Keeping skin and hair moist – if you’ve noticed that your hair, skin or lips are dry or scratchy, a humidifier could help to moisturise them.

Preventing nosebleeds – if you get frequent nosebleeds, it might be caused by dry nasal passages, in which case a humidifier could help to moisturise them and reduce the risk of nosebleeds happening.

A humidifier could also be useful around the home. Houseplants may benefit from the increased moisture in your home, while in warmer months, a humidifier can prevent wooden furniture from drying out and cracking. Humidity can also help to prevent wallpaper from cracking and static electricity from building up.

Humidifier features to look out for

Humidistat

A humidistat monitors moisture levels in the air, allowing you to keep track of the relative humidity level in the room. This function will help you keep the RH within the recommended range of 30-50%.

Size

Most humidifiers are small enough to sit on a bedside table, so you can have it on while you’re sleeping. However, the overall size will be dictated by the type of humidifier. 

Evaporative devices tend to be bigger because they need space for filters and fans. A wick filter can be quite large and takes up most of the space inside the casing. The size of the water tank will also have an effect on dimensions.

Run time and auto-shut-off

This is the amount of time the humidifier will work before it runs out of water. The larger the tank, the more time it can run for. Some devices, if set to the maximum setting, may run out after 7-8 hours, while others will last for around 15-16 hours.

Look for a humidifier that has auto shut-off. This is where the device will stop operating once the water has run out, and means you won’t be wasting energy unnecessarily.

Tank design

Make sure you choose a humidifier that has an easy-to-fill water tank. In our testing, we check how easy it is to carry the tank to the sink, and whether you can fit it under a standard kitchen sink tap to fill it. Some models we’ve tested are so tall that you’d need to use a filling device such as a watering can to fill the tank.

Aromatherapy

Many humidifiers give you the option of releasing aromatherapy scents alongside water vapour. This might be nice if you’re a bit bunged up from a cold, and you wanted a relaxing scent of eucalyptus or lavender. Be mindful, though, that many of the aromatherapy functions require you to buy brand-specific sponges to slot into the humidifier.

Smart options

Like many air treatment products, a smart humidifier is an option, whereby you can control the device via an app on your phone. So, for example, you could turn off a humidifier in your baby’s room without having to come in. We check the security of any smart models during our testing to make sure the app is easy to use and secure on your home network.

Timer

This allows the humidifier to turn itself off after a certain amount of time in operation.

Night mode

Some models offer a night mode, where LED lights are dimmed or switched off and digital displays are turned off.

How to keep your humidifier clean

It’s vital that you clean your humidifier regularly. Not only is this so that the unit works properly, but also to reduce the risk of spreading harmful bacteria or mould into the air.

If you fill your humidifier with water, use it for a bit, then leave the water in there for a week, it will begin to stagnate. At that point bacteria and microscopic mould spores may start developing in it.

If you then turn the device on without first emptying and cleaning it, you’ll be humidifying these bacteria and mould into the air, where they will be breathed in. This can have potentially serious health consequences, such as severe cough, worsening of asthma symptoms, fever, shortness of breath and, in worst-case scenarios, respiratory infections and even lung disease.

Every humidifier will have its own cleaning instructions, and guidance around frequency of cleaning, so make sure you read the instruction booklet thoroughly before first using it.

White vinegar is a good option to clean your humidifier, as it will also help to remove any limescale build-up, which could be a real problem if you live in a hard water area and are not using distilled water. Citric acid powder is also an option for cleaning. 

If you decide to use a bleaching cleaner such as Milton, make sure you fully rinse all the parts after soaking them in the bleach solution to remove any traces so everything doesn't end up smelling of bleach when you use the device.

Let all the parts of the humidifier air-dry before you reassemble it, and periodically sniff the different parts of the device – if you notice a dank or musty smell, it’s definitely time for another thorough clean.

Are humidifiers eco-friendly?

Humidifiers don’t use masses of energy compared to products such as dehumidifiers, air conditioners or electric heaters. However, they will use some energy, and it could be wasteful, especially if the device is used inefficiently. There are some simple ways to make sure your humidifier is not working harder than necessary:

Choose the right capacity for the size of your space, the amount of people living in it and how dry your room is. 

Keep the windows shut when you’re running a humidifier, so water vapour doesn’t escape. 

If available, make use of timer or automatic shut-off features so the humidifier isn’t running continuously while you’re out of the house or asleep.

Look at our test scores. Every humidifier we review has an energy efficiency rating, so our highest-scoring models are most likely to be the least wasteful.

Should I buy a second-hand humidifier?

You could save some money by buying a humidifier second-hand. If you’re purchasing from a private seller, be aware that, unlike retailers, they are not obliged to proactively highlight any faults. They should tell you if you specifically ask, though. 

One thing to be careful of is the cleanliness of a second-hand humidifier, due to the issues highlighted above. Even if the seller has assured you that it’s been cleaned, we’d recommend you give all washable parts a thorough clean and sterilisation to remove any germs or bacteria.

If you’ve bought a second-hand humidifier, read our guide to your rights when buying second-hand goods.

How do I dispose of a humidifier?

If you’re thinking about getting rid of your humidifier, it’s important to do so in a way that isn’t harmful to the environment. 

Look for the crossed-out wheelie bin symbol on your humidifier, as this is an indicator that it can be recycled. You may have to remove certain parts such as filters and put them in with your normal household waste. This information should be available in the humidifier manual.

Find out more about how to recycle your electrical items correctly.

How much does a humidifier cost?

Humidifiers can cost anything from around £20 up to £600, depending on the features and functions of the product.

The average price is around £70, and you’ll pay more if you want one with a humidistat, smart functionality, or if it also acts an air purifier.

Where to buy a humidifier

When shopping online, make sure you’re dealing with a reputable seller. Check the retailer's returns policy and also have a look at customer reviews.

Popular retailers that stock humidifiers include:

• Amazon has a vast selection of humidifiers for you to sift through, including large industrial-scale humidifiers that retail in the thousands. Big-name brands include Levoit, Pro Breeze and Electriq, as well as multiple obscure brands.
• Argos stocks a selection of humidifiers from Vicks, Dyson and Duux. Prices range from £50 to £600.
• Currys has humidifiers from Duux, Dyson, Tors + Olsson, Beldray and Logik.
• John Lewis stocks humidifier models from baby-specific brands such as Maxi Cosi, Babymoov and Fridababy.

Discover the retailers that are rated highly by Which? members with our expert guide on the best and worst shops.

How to make a homemade humidifier

If you’re looking for ways of increasing the humidity in your home without using a machine, there are other options.

A simple bowl of water next to a radiator or on a sunny windowsill is a starting point for a very rudimentary humidifier.

For a slightly more sophisticated approach, you can try a fan-style humidifier. You’ll need:

• Bowl or container of water
• Skewer that’s long enough to rest across the container
• Sponge or cloth
• Small fan

Either push the skewer through the top end of the sponge and hang it over the bowl so the lower half is touching the water, or fold the cloth over the skewer so it’s dangling in the water. 

Set a small fan up so it’s blowing over the bowl and skewer setup. 

As the water is wicked up the sponge or cloth, the fan will blow over it, helping to evaporate the moisture and send it into the room.

Be careful about storing water too close to electrical items such as fans.

You can also purchase radiator humidifier containers, which you fill with water and hang over a radiator. They then emit moisture as the area beside them warms up. They tend to be much cheaper than plug-in machines, especially as they don’t require any electricity.

You can dry damp laundry near a radiator, as the moisture in the clothes will evaporate from the clothes into the room.

You can increase humidity simply by having more house plants. Water evaporates from the stems and leaves of plants by a process called transpiration, so if you have lots in your home, you may notice the air seems less dry.