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1 September 2021

Best cooler bags

We tested a range of cooler bags – from the likes of Asda, Argos and Yeti – on insulation, leakage and durability, and the results were surprising
Olivia Woodhouse

With summer just around the corner, restrictions being lifted and restaurant reservations hard to come by, why not invest in a quality cooler bag and take your dinner and drinks outside? 

In April 2021 we tested nine cooler bags, including household favourites Asda and Argos, and a premium version from cooler bag specialists, Yeti. We put the bags through their paces across a number of areas including insulation, durability and how leakproof they are. 

We looked at how comfortable they were to carry and at the quality of their design. And to get a better understanding of their capacity, we filled each cooler bag full to the brim with drinks cans.

Pricing and availability last checked as of 1 September 2021.

The best cooler bags

Only logged-in Which? members can view the cooler bag test results below. If you're not yet a member, you'll see an alphabetically ordered list of the cooler bags we tested. Join Which? now to get instant access to our test scores and Best Buy recommendations below.

Hi gear cooler bag

Argos Home Blue Cool Bag

Cheapest price: £12, available at Argos

Dimensions: 33cm x 30cm x  30cm (H x W x D)  

Stated capacity: 22 litres

Can capacity: 48

Key features: two-year warranty

This cooler bag from Argos is the cheapest we tested. The bag has a simple boxy, polyester design with no bells or whistles. 

Log in or join Which? to find out how the Argos cooler bag compared with its pricier competition. 

Hi gear cooler bag

Hi Gear Self Inflating 30L Cooler

Cheapest price: £28.02, available at Amazon, also available at Blacks, Go Outdoors, Millets, Ultimate Outdoors

Dimensions: 36cm x 35cm x 25cm (H x W x D) 

Stated capacity: 30 litres

Can capacity: 53

Key features: Waterproof, leakproof, available in 20 and 25 litres

This 30-litre cooler bag doesn’t have the extra compartments, mesh holders or dividers seen on some of the other bags, however it does have a unique inflation ability. But did this make a difference to its insulation or is it just a gimmick?

Join Which? or log in to find out. 

Mountain Warehouse cool bag

Mountain Warehouse Patterned Cool Bag

Cheapest price: £9.99, available at Mountain Warehouse

Dimensions: 26cm x 35cm x 26cm (H x W x D)  

Stated capacity: 25 litres

Can capacity: 41

Key features: Additional mesh and zipped pockets, leakproof

One of the cheaper bags we tested, but it still has additional features such as mesh pockets, velcro straps for condensing and zipped pockets. 

Extras aside, want to know how it did in our testing? 

Join Which? Or log in to find out. 

Ozark Trail cooler backpack

Ozark Trail 24 Can Backpack Cooler

Cheapest price: £18, available in store at Asda

Dimensions: 26cm x 27cm x 19.1cm (H x W x D)  

Stated capacity: n/a 

Can capacity: 24

Key features: Additional mesh pockets and zipped pockets, leakproof

One of two backpack style cooler bags in our line up, this one has adjustable padded shoulder straps for added comfort. With a smaller capacity than the other bags we tested, it would be more suitable for a two-person picnic than a family camping trip. 

To unlock our results join Which? Or log in.

Polar Gear cooler bag

Polar Gear Premium Family Cooler Bag

Cheapest price: £12.50, available at Waitrose, also available at Amazon

Dimensions: 31cm x 36cm x 28cm (H x W x D)  

Stated capacity: 30 litres

Can capacity: 60

Key features: Additional pockets, two-year guarantee, leakproof, available in six litres and 16 litres

Polar Gear claims to have heat-sealed lining to avoid leakages. But how did it actually do in our leakage test?

To find out login in or join Which?.

Quechua cooler bag

Quechua Compact Cooler

Cheapest price: £29.99, available at Decathlon

Dimensions: 33cm x 35cm x 33cm (H x W x D)  

Stated capacity: 30 litres

Can capacity: 55

Key features: Mesh pockets, two-year warranty, available in 20 litres

This cooler bag from Decathlon has a compact design allowing it to be easily condensed for storage. It also claims to keep contents cool for nine hours without the use of ice packs, but did our testing confirm this?

To unlock our results join Which? or log in. 

Thermos Radience cooler bag

Thermos Radiance Cooler

Cheapest price: £19.87, available at Amazon, also available at Flasks Online, Thermos, Ryman

Dimensions: 32cm x 33cm x 27cm (H x W x D)  

Stated capacity: 30 litres

Can capacity: 50

Key features: Additional mesh pockets and zipper pockets, 12-month warranty, leakproof, water-resistant, available 8.5 litres and 16 litres

Thermos boasts its own unique IsoTec insulation – essentially, compact foam insulation within the walls of the main bag. It has an easy access lid, mesh pockets and additional zipped pockets.  

We’ve tried and tested Thermos flasks but how does the Thermos cooler bag compare?

Log in or join Which? To find out.

Titan Deep Freeze cooler bag

Titan Deep Freeze 40 Can Collapsible Cooler

Cheapest price: £17.89, available at Costco, also available at Amazon

Dimensions: 30cm x 35cm x 25cm (H x W x D) 

Stated capacity: n/a

Can capacity: 48

Key features: Additional mesh pockets and zipped pockets, lifetime warranty, leakproof

The Titan Deep Freeze cooler bag looks rugged and – with a number of extra compartments, mesh pockets and extra straps – it would appear to be the perfect bag for a camping trip. 

To find out how it did in our insulation test and to see whether it’s as rugged as it looks join Which? or log in. 

Vonshef cooler bag

VonShef Cooler Bag Large

Cheapest price: £19.99, available at Amazon

Dimensions: 23cm x 43cm x 24cm (H x W x D)  

Stated capacity: 30 litres

Can capacity: 46

Key features: Additional pockets, two-year warranty, leakproof, available in 22 litres

The only bag we tested with a hamper-style design. The cooler bag is held up by a rigid aluminium frame attached to a handle. This construction makes it great for storing away, but what’s its primary function like? 

Log in or join Which? to find out. 

Yeti Hopper Backflip 24 cooler backpack

Yeti Hopper Backflip 24

Cheapest price: £577.61, available at Amazon

Dimensions: 37.5cm x 31cm x 18cm (H x W x D)  

Stated capacity: 24 litres

Can capacity: 40

Key features: three-year warranty, leakproof, waterproof

Yeti is renowned for its high-performance cooler bags and this is reflected in the price – the Hopper Backflip 24 is the most expensive of the bags we tested. Its backpack design makes it a great option for chilling on the go. It also claims to be leakproof, waterproof, and have the ‘toughest zipper in the world.’ 

But just how tough was the Yeti cooler bag? Join Which? or login to find out.   

How best to pack a cooler bag

We got in touch with some cooler bag brands and our fridge expert to see if they had any tips on optimising your packing technique. 

Here’s what they had to say:

  • Chill your bag before you use it. This could be a sacrificial bag of ice or a few extra ice packs thrown in a few hours before packing. 
  • Fill your bag as much as possible. Leaving space in the bag means there’ll be more air and air accelerates the melting of ice. Yeti suggest filling space with towels or crumpled newspapers. 
  • Layer up. Layer your bag strategically so the things you’ll need last are at the bottom. Put ice packs between each layer and try to cover food to avoid it getting soggy.
  • Double up on ice. You should use twice the ice (ice blocks, ice packs or bagged ice) as your contents. The more ice, the more effective your cooler will be
  • Think twice before you drain cold water. Frozen items will heat up when in contact with cold water so if you want to keep them frozen our fridge expert suggests draining the water and adding more ice. However, if you just want to chill items cold water will be fine. 

Three things we discovered testing cooler bags

1. The difference in temperature change across the bags wasn’t huge. There was only a 2.7°C difference between the bag that heated up the most and the bag that heated up the least. 

So, while there was a winner, none of the bags were particularly bad at insulating. 

The Food Standards Agency recommend that you keep your fridge set at 5°C so that cold food stays at around 8°C. 

Though our water bottle temperatures were higher than that, temperature is relative and the more ice packs you use the cooler the bag will be. If you've got perishables, particularly food, you should be ensuring your cooler bag is 5°C or below.

2. Great insulation can be nullified by poor design. The bag that came out top in the insulation test was also the only bag to leak.  

3. A good zipper can make a world of difference. An easy-to-use zip means you can get in and out quickly avoiding hot air getting in and cold air getting out. We found that two bags had stiff zips. 

One was so tough it became a chore to open and another caught on the inner lining, eventually ripping it off.

How we tested these cooler bags

We put 11 cooler bags through their paces across a few key areas. 


We put a chilled bottle of water and an ice pack into each bag. The ice packs were kept in the freezer overnight and then left in the bags for 30 minutes before testing began. We attached thermocouples (a sensor for measuring temperature) into each bottle and left them for the day, taking temperature readings on the hour, every hour. 

To replicate typical use, we opened and closed the bags four hours in – and then every 30 minutes.

Leak proofing

We filled the bags with 500ml of water and left them sitting on top of a bed of paper towels for an hour. After the hour we checked for any leakage onto the towels and poured the water back into the measuring jug to see if any had been absorbed by the towels.


Bag leak in leak proof test.
This damp patch is from the only leaking bag we tested


We identified the stress points of the bags – usually the handles and straps – and tugged at them 10 times each. We carried out a visual inspection before and after to see if the bags incurred any damage.


We filled each bag with half their capacity in cans and carried them along the same route for five minutes. 

Build quality

We noted any extra features each bag had and tried the zips at the beginning and at the end of testing to see if they had been affected by our tests.

How we chose the cooler bags 

For our test we picked cooler bags that were strictly bags, not boxes. They had to be made of soft material.  

We then focused on bags that were more suitable for larger groups. Our research showed that a 'family size' bag typically falls into the 20 to 30 litre range. 

We ordered and paid for all the cooler bags that we tested. Which? doesn't accept freebies, which gives us the freedom to tell the truth about our test results.