Hydro Flask vs. S’well Bottle – Insulated Stainless Steel Water Bottle Comparison

Hydro Flask vs S'well BottleIf you’ve been anywhere near a major city within the last five or so years, you’ve probably seen a S’well Bottle or two. And you’ve certainly spotted a Hydro Flask. These brands have become so huge and popular across the globe that there is even a decent chance you’ve owned one. But if you’re thinking of purchasing a new one, the similarities between the two might leave you scratching your head. So for those who have always wanted an answer to the Hydro Flask vs. S’well debate, we’ve been comparing the two bottles to get you an answer.

Since both of our competitors offer double-wall insulated stainless steel bottles, it might be tempting to write them off as more-or-less the same. Yet there are certainly quite a few differences: in sizes, in appearances, in price, and in insulating capability, to name a few. To answer these questions (and a couple more!) we’ve been subjecting our Hydro Flasks and our S’well bottles to a battery of tests.

Let’s see what we found out.

Hydro Flask
24 Ounces
18/8 Food Grade Stainless Steel
24 Hours Cold/12 Hours Hot Insulation
Huge Variety of Colors and Designs
Variety of Sizes
Numerous Accessories
Buy on Amazon
S'well Bottle
25 Ounces
18/8 Food Grade Stainless Steel
24 Hours Cold/12 Hours Hot Insulation
Huge Variety of Colors and Designs
Two Sizes
Extremely Stylish Bottles
Buy on Amazon


Two Top Insulated Bottles: Analyzing Hydro Flask vs. S’well Detail-by-Detail

Pink Swell Bottle Action Shot
Probably the best way to kick off this competition is with a bit of praise for both bottles. In our recurring Best Water Bottles series, we’ve highlighted both Hydro Flask and S’well as winners of the prestigious title of Best Water Bottle of the Year. First it was the Hydro Flask, which we crowned Best Water Bottle of 2015. Two years later, we awarded S’well the title of Best Water Bottle 2017.

The whole range of Hydro Flask and S’well bottles are attractively stylish and exceptionally functional. Among our huge collection of stainless steel bottles, both Hydro Flask and S’well are at the top of the favorite list and certainly some of the most used bottles.

Both of our competitors are made from food-grade 18/8 stainless steel. They feature a double-wall vacuum insulated design to minimize heat transfer to keep the contents at more or less at the same temperature they were at when they went into the bottle. Both bottles are available in a range of attractive colors and designs.

But enough about the similarities. Let’s look at the differences. Of which there is one that particularly stands out.

The Major Difference Between Hydro Flask and S’well Water Bottles


The biggest single difference between our two competitors is the overall shape of the bottle. Where the Hydro Flask has a shape that has been widely adopted as the standard for insulated stainless steel bottles, the S’well maintains a distinctive shape for all o the sizes in their catalog. The biggest place this makes a difference is in the mouth of the bottle, or the opening, where you fill and drink from.

On Hydro Flasks, you can select a Wide-Mouth option which has a spacious opening that easily allows you to add ice or other bulky contents to your flask. In contrast, S’well bottles do not offer any type of Wide-Mouth option. They have openings slightly larger than, but comparable to, Standard Mouth Hydro Flask bottles. On the whole, S’well bottles are smaller than Hydro Flask. The largest S’well is just 25 ounces, whereas the largest Hydro Flask reaches up to 64 ounces.

S’well does benefit from its design, so it’s not all gripes about the mouth of the bottle. It’s much more comfortable to hold in the hand than a Hydro Flask or similarly shaped stainless steel water bottle. The design is more reminiscent of a disposable glass bottle than the jug-like design of the Hydro Flask.

Hydro Flask vs S’well Bottle Five Factor Comparison

As always when we compare two water bottles, we’ve tested and reviewed the Hydro Flask and S’well Bottles on five points of analysis:

  • Price
  • Insulation
  • Accessories
  • Durability
  • Form Factor

Below, we’ll be taking an in-depth look at how the two bottles compare on each of these points. At the end, we’ll tally it all up and see who is the ultimate winner of the Hydro Flask vs. S’well debate.

Bottle Price Factor

Verdict: Hydro Flask

Hydro Flask Action Shot

When it comes to price, both Hydro Flask and S’well are what we’d consider premium water bottles. But S’well bottles live at the high-end of the price spectrum. The 25-ounce S’well bottle will run you about $45. A 24-ounce Hydro Flask is around $10 cheaper, and you can get a 40 ounce Hydro Flask for less than the cost of the 25-ounce S’well.

If your budget is the major concern in differentiating these two bottles, we’d have to recommend you pick up a Hydro Flask. For the price factor, it’s important to keep in mind how closely these bottles actually perform. S’well has higher prices largely due to their popularity as a brand and their very unique designs. But in comparison to a top competitor such as Hydro Flask, the difference in price is more pronounced than the difference in quality.

Bottle Insulation Factor

Verdict: Tie

S'Well Bottle in Bottle Carrying Net

Hydro Flask and S’well make use of the same type of insulation and are manufactured from the same type of stainless steel. So it’s not too surprising that they would perform similarly. What we were surprised by was how similarly. In the past, we’ve repeatedly demonstrated how not all insulated bottles perform equally well. But these two seem to. So much so that we ended up calling this one a tie.

Insulated stainless steel bottles utilize a technique called Double-Wall Vacuum Insulation. This is where the bottle is constructed as a sort of “bottle-in-a-bottle” where there is a thin layer of evacuated air (vacuum) in between two walls of stainless steel. Since the vacuum is a very poor conductor of heat, the bottles offer exceptional insulation. Both S’well and Hydro Flask advertise their bottles as keeping cold liquids cold for up to 24 hours and hot liquids hot for up to 12.

We’ve developed a standard method of real-world testing for insulated bottles. The test is very simple: for our cold test, we filled each bottle with 40° Fahrenheit water with chunks of ice. We left the bottles to stand for 24 hours on our kitchen counter in the tropics at room temperature. After 24 hours, we found that the Hydro Flask had risen 5° and the S’well had risen 6°. We repeated the same test hoping to see more variety, but instead found ourselves at an exact tie. In the second test, both bottles had risen 6°.

We repeated a similar test, this time using hot water and letting the bottles stand for 12 hours. Each bottle was filled with 150° Fahrenheit water. After 12 hours, we found the Hydro Flask measuring 99° and the S’well bottle measuring 100°. Upon repeating the test, we found Hydro Flask again at 99° and S’well this time measuring 98°.

These numbers are so close to one another that we have decided this one is a tie. Either of these bottles won’t lead you astray in terms of insulation.

Bottle Accessories Factor

Verdict: Hydro Flask

Hydro Flasks in an assortment of sizes and colors

When it comes to having a water bottle you can accessorize, Hydro Flask is the undisputed champion. Out of every water bottle we’ve ever owned or reviewed, none has had a broader catalog of accessories available. You can customize your Hydro Flask with a huge selection of different lids, carriers, sleeves, and more. For some complete coverage on how you can customize your Hydro Flask, see our Guide to Hydro Flask Accessories.

S’well owners on the other hand won’t find any official S’well accessories. There are a few third party accessories that you can get. If you want a S’well straw lid, for example, you can pickup this ICONIQ Straw Cap which fits 17 ounce or 25 ounce S’well bottles. However, as with the few other S’well accessories we’ve seen, this straw cap is a third party design. For those looking for a different way to carry their S’well bottle, we’ve also found a bottle holder carabiner and a netted bottle holder which are worth checking out. But other than these few selections, the options for S’well accessories are sparse.

Bottle Durability Factor

Verdict: Tie

Hydro Flask vs Swell Bottles Closeup Photo
As is the norm with stainless steel water bottles, both the Hydro Flask and S’well are virtually indestructible for everyday use. The main concern is puncturing or cracking the exterior layer of the bottle, which shouldn’t cause a leak but will ruin the bottle’s insulation. However, this is something that would take a serious amount of force. Your bottle would need to fall from a great height when filled, be run over, or have some equally calamitous fate befall it before it would be anywhere near ruined.

In owning both S’well and Hydro Flask bottles for years, neither has given us any indication that they are anything less than supremely durable. Some of the fancier looking S’well bottles definitely seem more precious on account of their beautifully finished exteriors. These bottles could be considered less durable in the sense that they are more prone to showing their cosmetic damage, where scratches or chips in the finish could create blemishes on the bottle’s design. However, this isn’t something that impacts the overall function or usability of the bottle, just its appearance.

We have to call this one a tie.

Bottle Form Factor

Verdict: S’well Bottle

Abalone Swell Water Bottle

With beauty being in the eye of the beholder and all that jazz, this is the most subjective criteria on which we judge these bottles. But for Hydro Flask vs. S’well, we don’t think anyone will be too offended if we give the Form Factor point to S’well. As much as we admire the nifty and now classic look of Hydro Flask, S’well offers a diversity of colors and eye-catching designs unrivaled by pretty much any other water bottle manufacturer.

S’well’s commitment to interesting designs has seen them pumping out a seemingly endless array of bottles that are works of art in their own right. From S’well we can find designs that mimic the look of wood or marble, incorporate elegant floral prints, take the appearance of a diversity of textures, and return to simplicity with uniform bottles for those who just want to represent their favorite color.

Final Verdict

Winner: Hydro Flask

In the final analysis, we’ve settled the Hydro Flask vs. S’well debate in favor of the good old Hydro Flask. The final tally is 2-1 in favor of Hydro Flask, with 2 factors that were declared a tie. Here’s the breakdown:

  • For the Price factor the winner was Hydro Flask.
  • For the Insulation factor, we declared a Tie.
  • For the Accessories factor, the winner was Hydro Flask.
  • For the Durability factor, we declared a Tie.
  • For the Form factor, the winner was S’well Bottle.

Ultimately, we feel the S’well bottle is more of the style choice, where Hydro Flask represents the sturdy and reliable work horse. If you want a stylish, neat-looking bottle with a comfortable form factor but a somewhat limited capacity (25oz being the largest size,) S’well Bottle is for you. But if you want a high-capacity, slightly more down-to-earth water bottle, Hydro Flask is a wining option.

Fortunately for all of us, both Hydro Flask and S’well are exceptional products. We don’t think you would be disappointed with either purchase. But on overall value, we’ve awarded the crown to Hydro Flask. That said, the S’well will certainly appeal to many who find the Hydro Flask’s bulk and monotone colors to be a little drab.

Learn More About Hydro Flask

Hydro Flask has been a huge part of our day-to-day lives for many years now. Not only do we fill, carry, and drink from them nearly daily, we’ve written extensively about them. To learn more about Hydro Flask, check out any of the links below:

Learn More About S’well Bottle

For a comprehensive look at what the S’well bottle offers, read our complete review of S’well Bottles.

If you’d like to check current prices, read other customer reviews, learn more specific details, or purchase a S’well Bottle of your own, be sure to visit the Amazon listing.

Other Hydro Flask Comparisons & Water Bottle Reviews

If you didn’t find out everything you needed from this article, be sure to browse some of our other articles on stainless steel water bottles. You might find Hydro Flask vs Klean Kanteen to be of use. Or Hydro Flask vs Takeya Thermoflask is a good choice if you want to see Hydro Flask paired off against a more affordable insulated bottle. But if you’re only after the best, see who came out on top in our Hydro Flask vs YETI Rambler contest.

Still can’t find what you’re looking for? Head to our ever-expanding Water Bottle Reviews and browse through the wealth of available options. Good luck finding the perfect bottle and remember to stay hydrated!

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We examine the Hydro Flask vs. S'well Bottle debate to figure out which of these leading insulated bottles is the best pick for your needs.

2 thoughts on “Hydro Flask vs. S’well Bottle – Insulated Stainless Steel Water Bottle Comparison”

  1. Hi, some of the information above is incorrect, the S’well water bottle has TRIPPLE WALL INSULATION instead of 2. And Hydro Flask has 2.


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