Under Armour vs Yeti Water Bottle

In this article, I’ll take a closer look at two of the most popular thermos bottles made by these companies – Under Armour’s Beyond bottle and Yeti’s Rambler bottle. And while both of these flasks have the same volume, there are still a few differences that might make you choose one over the other.  

Under Armour Beyond 18 oz Bottle 

Under Armour bottle


  • Weight: 0.7 lbs 
  • Material: Stainless steel 
  • Colors Available: 20
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There’s a lot to like about this relatively inexpensive thermos bottle. While it’s not as high-performing as its rival when it comes to temperature regulation, Under Armour Beyond 18 oz is a very durable product and one that’s equipped with several convenient features, like the carry loop or the lockable, leak-resistant lid. 

This model weighs less than Yeti – if you like to keep your backpack as light as possible, UA’s Beyond stainless steel bottle is a great option. 


  • A durable & relatively inexpensive thermos bottle 
  • Lockable, leak-resistant lid 
  • Lightweight


  • Not the best temperature regulation

Yeti Rambler 18 oz Bottle 

Yeti rambler thermos


  • Weight: 1.16 lbs 
  • Material: Stainless steel 
  • Colors Available: 21

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It’s no wonder that this thermos bottle is one of Yeti’s best-selling products. Besides the fact that it easily withstands daily wear and tear due to its superb construction, the Rambler 18 oz also provides outstanding temperature regulation with its double-walled vacuum insulation. 

Other features worth mentioning are the 3-finger carrying handle, the easy-to-use Chug Cap, as well as the fade and peel-resistant DuraCoat finish. Unfortunately, the bottle’s rugged, high-performing construction makes it significantly heavier than its rival. If you are interested in similar brands, check out our Yeti vs Iron Flask comparison and Yeti vs Hydro Flask comparison.

The Comparison 

The Construction Quality

Cyan Yeti Thermos

Yeti’s immensely popular Rambler 18 oz bottle sports 18/8 stainless steel construction and is as durable as a product of this type can be. The model easily withstands daily wear and tear and is far less susceptible to scratches and dents than the cheap reusable bottles made by no-name brands. 

Even though it costs less than its rival, the Under Armour’s Beyond thermos bottle is just as hard-wearing and long-lasting. It is also made of stainless steel and features a construction that you can count on. Like Yeti’s model, it ended up with only a few (very) minor scratches during my drop tests. 

If you’re looking for a durable thermos bottle, you can’t make a mistake by going with either of these two models. Both are incredibly well-made and should last for years as long as you take good care of them. 

The Performance

Man holding a silver steel bottle

The main reason folks choose these kinds of bottles over plastic ones is their capability to maintain the temperatures of both hot and cold drinks. 

This is where Yeti shines the brightest. While it’s not capable of keeping hot tea hot for 12 hours – as its manufacturer claims – the Rambler 18 oz will keep your warm beverage warm for at least 8 hours, which should be more than enough for most people. And when it comes to keeping cold drinks cold, the model is one of the best in the market: it effortlessly keeps water at a cool temperature for more than 24 hours. 

During my tests, I determined that UA’s Beyond bottle can keep a hot drink hot for about 6 hours and a cold drink cold for around 18 hours. Obviously, this means that Yeti’s thermos bottle is the winner in this category. However, keep in mind that the UA’s offering costs less and that not everybody requires the best possible thermoregulation performance for their outdoor adventures. 

So, if you want your thermos bottle to maintain the temperature of your favorite drinks for as long as possible, the Rambler 18 oz is undoubtedly a better choice. If you’re looking to save some money, go with the Beyond bottle – you won’t be losing too much in terms of performance. 

The Weight 

A lot of people don’t consider weight an important factor. But when your backpack is full to the brim, the last thing you need is additional weight that will slow you down even more. 

Under Armour Beyond 18 oz bottle is a clear winner in this category. Although it has the same volume, it weighs significantly less than its rival and is undoubtedly a better choice for ultralight backpackers. I should also point out that this model is very stable when placed on a flat surface in the upright position. 

Yeti weighs 0.46 pounds more than the UA’s Beyond model and is not the best choice if you want your thermos to be as lightweight as possible. However, this bottle’s increased weight is a direct consequence of its superior insulation. In other words, yes, it weighs more, but it’s also better at keeping coffee, tea, and other drinks hot for hours. 

In summary, if low weight is really important to you, the UA’s Beyond bottle is the better option. The model weighs only 0.7 pounds and definitely won’t weigh you down during your ultralight backpacking trips.

In discussions revolving around Hydrapeak versus Yeti in the insulated bottle market, weight and insulation efficacy are often pivotal points of comparison. Hydrapeak, like Yeti, balances a lightweight design with effective insulation, providing a practical solution for those who prioritize carrying convenience without compromising on performance.

The Features

Yeti Thermos Bottles

Stainless steel bottles are relatively simple. Most of them have a body that’s typically covered with some slip-free coating, built-in insulation, and a cap – that’s pretty much it. 

The best of the additional features found on the Yeti Rambler is the wide 3-finger carrying handle on its Chug Cap. This feature makes carrying the thermos bottle as easy as it gets. The DuraCoat finish also deserves a mention since it’s resistant to peeling, cracking, and fading. 

The Under Armour thermos bottle features a very convenient, lockable, and leak-resistant lid – it’s one of the best things about this product. It also has a non-slip silicone bottom, whose purpose is to make the bottle stable on flat surfaces, and a carry loop for easy transportation. 

As you can see, both of these models are feature-rich compared to many of the other products of this type available on today’s market.

In the Stanley vs Yeti comparison, Stanley thermos bottles stand out with their iconic green design and a legacy of durability. Much like the Yeti Rambler, the Stanley bottle boasts impressive insulation capabilities, ensuring your drinks stay at the desired temperature for hours.

Under Armour vs Yeti – The Verdict 

The higher price of Yeti’s immensely popular Rambler thermos bottle is entirely justified – this is a genuinely well-made and high-performing product that easily wins this “bottle battle.” 

However, that is not to say that Under Armour’s Beyond thermos bottle doesn’t deserve your attention. If you’re on a budget, this model is a solid choice: it won’t maintain the temperature of your drinks for as long as the Yeti bottle, but it weighs significantly less while being just as durable and feature-rich. 

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