Despite the unpredictability of British weather, many of us will be happily and determinedly socialising outside. Cool boxes are an incredibly practical investment for a number of reasons, but mainly because they’re a simple solution for safely storing food at a colder temperature – excellent for a picnic or barbecue.
Electric cool boxes can be plugged into your car for travelling, while cooler bags and backpacks are a great choice for slinging onto your shoulder for adventures.
There are plenty of options on the market, and thinking about how you’ll use your purchase will help you make the right choice for you. Prices can range from the very cheap to the hugely expensive, so frequency of use and the need for portability are key factors to consider. To help you choose, we carefully longlisted and tested a selection from a range of brands to hit all budgets.
Read on to discover our top cool boxes. For more on eating in the great outdoors, check out some of favourite seasonal recipes from spring desserts to family picnic recipes and easy traybake dinners. We’ve tested all the kit you’ll need for al fresco dining: check out our reviews of the best camping stoves, best picnic gadgets and best picnic hampers.
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How to choose the best cool box
Depending on where you’re planning to use your cooler will affect your choice. They are often made from heavy duty plastic and insulated with polyurethane foam, which tends to keep food colder for longer. In most cases, you’ll need to add ice packs to keep the temperature down.
Cool bags are generally lighter than cool boxes and once emptied, you can pack them down for easier storage. You may forfeit capacity for portability as the largest bags will be the heaviest to carry when loaded – which is when wheeled options come into play. In all cases, think about size. Do you want to be able to stand a litre bottle upright inside, or perhaps you have a casserole dish that needs to sit comfortably in the base?
Electric cool bags and boxes with a cigarette-lighter charging cable are ideal if you’re heading on a long car journey. They increase the duration of cooling, but will add more weight. Once you’ve decided the type of activity you require a cool box for, we recommend considering the following in order to buy one that fulfils every need:
- Weight: a cool box for keeping drinks cold in the garden can be weighty, but if you’re travelling with it over a short distance, a lighter option with wheels will be better
- Capacity: how many people will you be catering for? The size of cool bags are often described in litres rather than people, but as a rule of thumb, 18 litres will carry between 25-28 cans, 30 litres will fit around 50, and anything above this will be large enough for a variety of food and drink vessels
- Bag or box: if portability is the goal, cool bags are a much more flexible for transporting, often featuring straps for carrying it over the shoulder or as a rucksack
- Durability: you want to be confident that a fully packed cool bag or box will be able to support the weight, and also won’t be let down by its handles, straps or wheels when you attempt to move it
- Easy-clean inner: cool boxes should be wipe-clean and rinsible
- Waterproof capabilities: particularly important for cooler bags if you’re taking them out and about, but also that the lining is leakproof
Best cool boxes at a glance
- Best cooler bag for versatility: Red Original waterproof 30l cooler bag, £179.99
- Best tote cooler bag: Hydroflask 20l insulated tote cool bag, £61.95
- Best affordable cooler backpack: Kuyou 45l cooler backpack, £43.99
- Best traditional picnic cooler basket: Silver Editions Green Tweed cooler basket, £49.99
- Best cooler backpack: Red Original insulated cooler cooler backpack, £134.95
- Best budget cool box: Campos cool box 29l, £20
- Best all-round cool box: Outwell Ecocool slate grey cool box 24l, £65
- Best space-saving cool bag: Mobicool 12V thermoelectric 32l cool bag MB32, £57.95
- Best mid-range cool box: Halfords 24l electric coolbox, £65
- Best cool box for carrying large quantities: Coleman 50 QT wheeled xtreme cooler, £98.95
Best cool boxes to buy in 2021
Red Waterproof cooler bag (30l)
- Available from RED (£179.95)
Best cooler bag for versatility
- Waterproof and leakproof
- BPA-free lining
- Zipper lubricant included
- Additional shoulder strap
- Stiff zip
- Strong ‘new product’ smell
Star rating: 5/5
This is a cooler bag-box hybrid, equipped with carry straps and additional handles, with a robust exterior that’s self-supporting. It has impressive cooling capabilities, living up to the 72-hour credential for keeping ice frozen (with a bit of melt). It’s also practical. The body is reinforced and waterproof, with a YKK Aquaseal zip designed to keep water out and leaks in. There are two side pockets and wave webbing, a luggage tension system for attaching it to your boat, roof or car. If you’re after an easy-to-carry cooler box for adventures that’s large enough for a family of six, this is our top recommendation.
Available from RED (£179.95)
Hydroflask insulated tote cool bag (20l)
- Available from: Alpine Trek, £61.95
Best tote cooler bag
- Contemporary style
- Waterproof exterior
- Expensive for a tote bag
Star rating: 4.5/5
Known for its water bottles and insulated thermal flasks, Hydroflask has designed this excellent insulated tote. Its polyethylene foam insulation kept food chilled for four hours with ice blocks inside. It’s a practical size, comfortably fitting a standing wine bottle, plus plenty of food for four people. You wouldn’t want to overpack it because of the shoulder-strap design, but it’s surprisingly comfortable to wear.
Available from Alpine Trek, £61.95
Red 15L insulated cooler backpack
- Available from Red Original £134.95
Best insulated cooler backpack
- Excellent insulation
- Eco-conscious TPU
- BPA-free inner lining
- Stiff top zipper
The boxy external structure of this backpack is self -supporting, covered with an impressively durable TPU fabric. The padded straps and back panel made wearing it a comfortable experience, although the chest strap came into play when fully loaded. We found its 15L capacity was enough space to stack lunch for four, helped by the two high bottle pouches which encased a tall water bottle in one side and two cans of beer stacked in the other. The only downside is the stiffness of its zip – responsible for it’s impressive leakproof credentials. The added bungee storage pocket held a scrunched up jacket whilst keys and a phone fitted in the top zip pouch.
Available from Red Original (£134.95)
Silver Editions green tweed cooler basket
Best traditional picnic cooler basket for two
- Wire-reinforced willow exterior
- Practical upright design for carrying
- No accompanying picnic rug
Star rating: 3.5/5
We love the classic look and feel of this cooler. Its upright design means it doesn’t bang against your leg as you walk, unlike more traditional baskets. Although a rug isn’t included, the handles are perfect for looping over your own once rolled. We fitted four medium food boxes stacked inside this basket, plus a bottle of wine, two glasses, plates and extra nibbles. The handles are wire-reinforced for added strength when full. This is a relatively affordable and classically designed cooler picnic basket built to be enjoyed by two.
Campos cool box (29l)
Best budget cool box
- Good insulation
- No wheels
This cooler is lightweight without compromising on sturdiness, making it ideal if you need to carry your supplies over a distance. It also holds 29 litres, so you can really load it up. It’s possible to stand six 1.5-litre bottles in the base, which means soft drinks are covered, as well as wine. We found it retained the temperature well, with a good seal and insulation.
Outwell Ecocool slate grey cool box (24l)
- Available from: Halfords (£65)
Best all-round cool box
- Powered by in-car socket
- Cable storage in lid
- Treated with a biocidal product for antibacterial effect
- Air vents must not be blocked
- Energy rating F on the EEI scale despite its ‘eco’ name
This cooler ticked all of our boxes, from great cooling capacity to performance. It’s a well-thought-out bit of kit. There’s a rectangular water bottle which doubles as an ice pack and slots handily in the box as a divider, helping to maintain a low temperature. It can be powered both to heat and cool, either in the car or with a mains plug, giving it versatility. Effort has obviously gone into the technology behind its energy efficiency, but its performance is more impressive than the eco credentials its name suggests.
Mobicool 12V thermoelectric cool bag MB32 (32l)
Best space-saving cool bag
- In-car socket for travelling
- Adjustable shoulder strap
- Not free-standing so needs propping up during travel in a car
Cool boxes are generally more effective than bags when it comes to insulation, but this Mobicool bag deserves its place in the line-up. It proved very effective in its own right, and with an in-car socket, you’re given the option of extending that time over long journeys. Being a bag, it’s also lighter than the boxes with a cooling mechanism, and has the benefit of folding to a smaller size once empty.
Halfords electric coolbox (24l)
Available from: Halfords (£70)
Best mid-range cool box
- Wipe-clean interior
- Practical size and shape
- Relatively heavy
We liked this cooler for its ultra-practical appeal. With a 24-litre capacity, including room to stand two large bottles, an in-car socket and a streamlined shape, we felt it offered a lot for its price tag. Mains adaptors are available at extra cost. The insulation proved very effective and, as with all electric models, the weight lends itself to short walks beyond the car.
Coleman 50 QT wheeled xtreme cooler
Best cool box for carrying large quantities
- Huge capacity
- Practical ‘landscape’ shape perfect for stacking
- Robust wheels and handle
- Chunky to store when not in use
This cool box holds a whopping 47 litres, yet is surprisingly lightweight when empty. It comes with a set of wheels and a handle, making it manageable even when packed to the brim. The plughole at the bottom is a nice detail – if you’ve filled it with ice, you can easily drain the water away.
Kuyou cooler backpack (45l)
Best affordable cooler backpack
- Huge capacity
- Padded back and straps
- Cheap-feel and impractical picnic mat included
Star rating: 4/5
With a rucksack this size, you need robust and comfortable straps with a supportive back padding, and the Kuyou offers both. The square base is practical for stacking square pots of food. Vertical storage requires some more strategic thinking, but a single exterior bottle sleeve allows a bit more wiggle room.
Some thought has gone into how to make this as practical as possible, including a wipeable inner surface and the adjustable straps across its front, perfect for holding a folded picnic rug or mat. A picnic rug is included, but being small and white in colour, it proved a bit impractical. Additional reinforced side handles and a bottle opener are also nice extras. Ice remained frozen for eight hours.
How we tested cool boxes
Sturdiness: coolers are often heavy when they’re packed, as the weight of cans, ice blocks and food all adds up. We wanted handles that made it easy to hold.
Portability: unless you’re only planning to use your cool box in the garden or for fridge overflow, portability is important. Extra points were given where coolers were especially easy to transport.
Keep-cool capability: this was key to our choices, being the primary function of a cool bag or box. A good seal and effective insulation were a must.
Additional features: in-car electric chargers, wheels, drinks holders and easy-carry options were well rated among the sea of products on the market.
Easy to use and clean: anything that carries food needs to be easily cleaned before and after use, so we looked for interiors that could be easily wiped clean.
How we tested: we filled each of the coolers with bags of ice, ice packs, drinks and typical picnic foods. We then checked the contents at intervals using a thermometer and timed how long it took for the ice cubes to melt.
Planning a barbecue or picnic?
For more product picks, visit our reviews section.
This review was written in May 2021. If you have any questions, suggestions for future reviews or spot anything that has changed in price or availability, please get in touch at email@example.com.
Do you own a cool box or bag? Tell us what makes it a great choice of cooler below…