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Best cooler bags for picnics, cooling drinks and summer
The best cooler bags – whether a cool bag rucksack, a small cool bag or a traditional over-the-shoulder type – keep your picnic treats and drinks chilled on one of those precious days of sunshine.
We've tested small cool bags, including the Cameron Thermos, and cool bag rucksacks from Igloo and Quechua, evaluating them for insulation, durability, comfort and their leakproof prowess.
Two of our three Best Buy recommendations come in at less than £30 – so paying more doesn't necessarily mean you'll get the best.
The best cooler bags
Only logged-in Which? members can view the cooler bag test results below.
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| Cooler bag | Capacity (no. of cans) | Insulation | Leakproof? | Durability | Where to buy |
|---|---|---|---|---|---|
| Excellent | Yes | Good | |||
| Good | Yes | Excellent | |||
| Good | Yes | Excellent | |||
| Excellent | Yes | Excellent | |||
| Good | Yes | Excellent | |||
| Average | Yes | Excellent | |||
| Average | Yes | Good |
Date tested: April 2021 and May 2023. Page last checked: July 2024. Capacity: measured with 330ml soft drink cans. We are not able to show every retailer and cheaper prices may be available.
The cooler bags we tested
All the cooler bags we tested are listed in alphabetical order below.
Only logged-in Which? members can view the best cooler bags from our tests.
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Cameron Thermos 24 Can Picnic Small Cool Bag
Available from Argos (£24)
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Most recently tested May 2023
Capacity 16 litres or 24 x 330ml cans
Size (HxWxD) 22 x 29 x 25cm
Need to know Front pocket and access hatch in lid; one-year guarantee
Hi Gear Self Inflating 30L Cooler
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Most recently tested May 2023
Capacity 30 litres or 45 x 330ml cans
Size (HxWxD) 41 x 44 x 26cm
Need to know Also available in 20 and 25 litre sizes
Igloo Maxcold Voyager Rucksack Cool Bag
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Most recently tested May 2023
Capacity Not stated in litres, we measured 24 x 330ml cans
Size (HxWxD) 43 x 31 x 27cm
Need to know Mesh side pockets, front and top pockets, bottle opener on right shoulder strap; one-year warranty; exterior made from recycled plastic bottles; other colours available
Lifewit Soft Cooler Bag
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Most recently tested May 2023
Capacity 30 litres, we measured 45 x 330ml cans
Size (HxWxD) 41 x 44 x 26cm
Need to know Mesh side pockets; also available in 20 litre and 40 litre sizes; other colours available
Polar Gear Premium Family Cooler Bag
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Most recently tested April 2021
Capacity 30 litres, or 60 x 330ml cans
Size (HxWxD) 30 x 34 x 28cm
Need to know Additional front pocket and access hatch in lid; two-year guarantee; also available in 6 and 16 litre sizes
See our reviews of the best cool boxes
Quechua Compact Cooler
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Most recently tested April 2021
Capacity 30 litres or 55 x 330ml cans
Size (HxWxD) 33 x 35 x 33cm
Need to know Mesh side pockets; two-year warranty; also available in 20 litres
Quechua Isothermal Rucksack Cool Bag
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Most recently tested May 2023
Capacity 30 litres or 43 x 330ml cans
Size (HxWxD) 50 x 32 x 25cm
Need to know Mesh side pockets, zip front and top pockets; back can be unzipped; mesh pockets on inside of the backpack; two-year warranty; also available in 10 and 20 litre sizes; other colours available
Thermos Radiance Cooler
Available from Amazon (£28.99)
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Most recently tested April 2021
Capacity 30 litres or 50 x 330ml cans
Size (HxWxD) 34 x 33 x 27cm
Need to know Additional mesh side pockets and zipper pockets; 1-year warranty; also available 8.5 litres and 16 litre sizes
Titan Deep Freeze 40 Can Collapsible Cooler
Available from Costco (£29.98)
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Most recently tested April 2021
Capacity Not stated in litres, we measured 48 x 330ml cans
Size (HxWxD) 30 x 35 x 25cm
Need to know Additional mesh pockets and zipped pockets; lifetime warranty
Yeti Hopper Flip 18 Soft Cooler Bag
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Most recently tested May 2023
Capacity 23.4 litres, 30 x 330ml cans
Size (HxWxD) 33 x 41 x 27cm
Need to know States that it's leakproof; you can attach tools and accessories to the front of it; three-year warranty; also available in 11.4 litre and 15.8 litre sizes; other colours available
Hot drinks on the go – Best vacuum flasks
How we test cooler bags
We choose the most popular cooler bags available at UK retailers, and pay for every one we test.
We regularly revisit the cool bags on sale to see if there are any new and popular models that need testing, and when we find them, we do.
Insulation
- We put a chilled water bottle in each cool bag, along with an ice pack, and measure the temperature increase over the course of the day.
- To replicate getting bits in and out of the bag, we open and close it at regular intervals throughout the test.
- All the cool bags we tested so far perform decently, but the best ones keep water cool all day.
Leakproof
- We fill the bags with water and leave them for an hour to see if they leak.
- We also evaluate how easy it is to clean up a spill on the inside of each bag.
Comfort
- Each bag is half-filled and carried to evaluate and identify any discomfort.
- The best cool bags are comfy, don't hurt your side or back, and have adjustable straps to find your perfect comfort.
Durability
- Each bag's zips, straps and pockets are forcibly tugged and inspected to see if bags incurs any damage.
- The best cool bags are solid and durable; the worst had the exterior casing rip after only one strong tug.
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How does a cool bag work?
A cool bag keeps food and drink cool by insulating it from the outside environment.
They usually have three layers: a strong fabric on the outside made from polyester or nylon; an insulating layer that's usually foam or air; and an inner layer, such as foil or plastic, that has some water resistance to prevent any spills from leaking.
Our testing found, however, that some cool bags were definitely not leakproof.
Cool bags usually have zips to seal the main compartment, keeping the inside airtight and the contents cooler for longer. A good zip makes a world of difference. It means you can get your food and drinks in and out quickly, avoiding hot air replacing cold air.
Our tests found stiff zips might be good for battling the elements on a long hike, but are less practical for grabbing beers every 10 minutes.
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How long do cool bags work?
Claims on how long they keep your food cool for vary from product to product, from a few hours to several days.
The Food Standards Agency recommends you keep your fridge set at 5°C, so that cold food stays at around 8°C. You'll want to keep your bag below 5°C, especially if you have perishables, for as long as you want to keep eating and drinking stuff from the bag.
Though our water bottle temperatures were higher than that on our tests, we deliberately only used one ice pack so it was the quality of the insulation that determined how cool the contents stayed, allowing us to be sure which were the best cool bags.
There are several things that you can do to make your cool bag work for longer:
- Chill your bag before you use it Use some sacrificial ice or ice packs a few hours before packing it.
- Use as many ice packs as you can The more ice packs you use, the cooler the bag will be. We tried our bags with two packs to put this to the test and they all performed better. A good rule of thumb is twice the volume of ice or ice packs to your food and drink.
- Layer strategically Put things you need last at the bottom, so when you go rummaging in the bag, it's for the shortest amount of time possible.
- Fill the bag as much as possible Leaving less space means there is less air in the bag. Air accelerates the melting of ice and ice packs, so fill the gaps with towels or newspaper.
Is a cool bag better than a cool box?
Whether a cool bag or cool box is right for you depends on your needs.
Our tests found cool boxes, on average, keep the contents colder for longer. However, they are bigger, heavier and less convenient to store when not in use than a cool bag.
If you're going for a picnic, festival or need lunch while out on a walk, a cool bag will probably be the better option. For parties, long car trips or camping holidays, a cool box, or even an electric cool box, might suit your needs better.
For a more detailed look at the differences read our cool boxes vs cool bags deep dive.
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