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Hydro Flask Unbound 22L Review

A mediocre performance for a high-end price
Hydro Flask Unbound 22L
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Price:  $200 List
Pros:  Handy pockets, backpack carry, durable, leakproof zipper
Cons:  Not impressive insulation, tips over easily, very stiff, expensive
Manufacturer:   Hydro Flask
By Maggie Brandenburg ⋅ Senior Review Editor  ⋅  Nov 15, 2019
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  • Insulation Value - 30% 4.0
  • Ease of Use - 25% 5.0
  • Portability - 25% 7.0
  • Durability - 20% 7.0

Our Verdict

The Hydro Flask Unbound 22L is a stylish backpack cooler with some helpful features, but relatively unimpressive insulation. It has extra pockets and a chic design that we like, but it tips over quite easily, is very stiff for carrying, and the back padding is a sweat-collection trap. Though it's quite durable, the insulation and the carrying experience don't live up to the competition.

Our Analysis and Test Results

The Hydro Flask Unbound 22L is a waterproof backpack cooler with a 420D nylon shell and welded seams. It features thick back padding and stiff, upright design.

Performance Comparison

Three backpack coolers included in our tests, from left to right:...
Three backpack coolers included in our tests, from left to right: Ice Mule Pro, Igloo Outdoorsman Gizmo, Hydro Flask Unbound.
Credit: Maggie Brandenburg

Insulation Value

The Hydro Flask Unbound has thick insulation and a watertight zipper, like many other models we tested. Unfortunately, this cooler still had an unimpressive insulation performance. The Unbound retained just 1.5 days of FDA-recommended food-safe temperatures, and even that was sketchy. The actual internal temperature fluctuated above and below 40ºF during those 36 hours before finally crossing that threshold for the last time. For this reason, we wouldn't recommend keeping items that have to be kept cold in this cooler (like raw meats), but it still works for beers and sandwiches and things that taste better on ice. While we aren't impressed by the insulation of this pack, it does have a leakproof zipper, provided you remember to close it fully.

A comparison of backpack coolers in our laboratory insulation testing.
A comparison of backpack coolers in our laboratory insulation testing.
Credit: Maggie Brandenburg

Ease of Use

The Hydro Flask has three extra pockets that make it fairly nice to use. One on each side of the body (one zippered and one open top) and a large one comprising the inside of the lid, but accessible from the back of the pack. The lid pocket is quite large, though the zipper opening is rather small, making for a tight squeeze to get items in and out. Like many of the watertight zippers we tested, the Hydro Flask main zipper is a bit challenging to use. It's a bit tough to pull and goes around all four corners, adding to the challenge. A bit of zipper lubricant goes a long way, but you'll pay extra for that. Loading this cooler isn't bad once it's broken in enough that the lid stays open on its own. The Unbound's tall, thin design makes it a tipping hazard both during loading and anytime you set it down.

The top pocket is hard to get in and out of, due to this too short...
The top pocket is hard to get in and out of, due to this too short zipper.
Credit: Maggie Brandenburg


This backpack cooler makes carting your picnic around much more pleasant than a messenger-style cooler. That said, we tested several backpack coolers, and this one isn't our favorite - that goes to the IceMule Pro, our Top Pick for carrying your cold goods long distances. While the Hydro Flask has thickly padded back panel and shoulder straps, the shoulder straps are rather close together for individuals with broader shoulders and the back panel is a sweat trap on hot days. Additionally, this is the most rigid of the backpack coolers, and combined with a fairly short torso length, means you can feel the bottom edge of the cooler bumping uncomfortably on your lower back. We do appreciate the utility of the removable sternum strap though, and will gladly take a loaded down backpack cooler over a single-sided carry any day.

This full back panel quickly became full of sweat.
This full back panel quickly became full of sweat.
Credit: Maggie Brandenburg


This cooler is built to last. With a 420D nylon shell that's puncture, tear, and abrasion-resistant and welded seams to boot, the Unbound feels solid and sturdy. All seams are well constructed, and even the plastic pieces seem to be of good quality. We did have a bit of a funk going on inside this cooler at first from a spilled container of food. But once the lid was broken in and would stay open on its own, the smell dissipated easily. Even the zipper pulls are hardy and withstood all the yanking and tugging we gave them. Hydro Flask also backs this cooler with a solid five-year manufacturer's warranty.

The Hydro Flask Unbound withstood being dragged in the sand and...
The Hydro Flask Unbound withstood being dragged in the sand and sitting in a wet kayak for hours on end.
Credit: Maggie Brandenburg


This is one of the more expensive coolers in this review. For the price, we expected more than the unimpressive insulation, not ideal backpack comfort, and awkwardly tippy shape and hard to use pockets we found. Unless you're head over heels for the look of this backpack, we think there are far better deals out there.

Click to enlarge
Click to enlarge


With a big name and a big price tag, we were expecting to like this backpack cooler more than we do. It's not a bad cooler - we enjoy the handy side pockets, the durable construction and leakproof zipper, and the useful backpack carry. But for the exceptionally high price, we expected better performance than it gives.

This shape is not our favorite to carry on long hikes.
This shape is not our favorite to carry on long hikes.
Credit: Maggie Brandenburg

Maggie Brandenburg
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