ThermoFlask vs Hydro Flask • The Unbelievable Results

Last updated Feb 15, 2020

Welcome to our ThermoFlask vs Hydro Flask Comparison. In this showdown, we’ll see which insulated water bottle is the sure winner. By the time you leave here, you’ll know for sure which bottle is the better pick for you. The insulated water bottle space is becoming more crowded by the day as new companies continue to pop up, some of them good while others are inferior copycats.

Today, we’ll see if ThermoFlask knows how to make a superior water bottle or if they’re just another Hydro Flask imitator. Below, we’ll compare the sizes, key features of each bottle, see which bottle is better at retaining hot/cold temps, current customer reviews, our two cents, and other necessary tidbits that helped us draw our conclusion.

Let’s start by putting the two bottles head-to-head in a feature comparison.

ThermoFlask vs Hydro Flask: Sizes & Features

ThermoFlask 2-Pack (24, 40 oz Sizes)

thermoflask vs hydro flask sizes and features 2

Hydro Flask (12, 18, 21, 24, 32, 40, 64 oz Sizes)

thermoflask vs hydro flask sizes and features

The ThermoFlask is currently available in 2-packs only in 24 and 40 oz sizes. The Hydro Flask has more available sizes from 18 oz all the way up to 64 oz.

Feature Comparison

  • Both bottles are made of food-grade 18/8 stainless steel
  • Both bottles are BPA-Free
  • They both advertise temperature retention times of up to 24 hours for cold beverages and 12 hours for hot beverages
  • The standard lids are different – ThermFlask offers a leakproof twist cap for easier sipping while the Hydro Flask wide-mouth lid covers the entire container and must be removed and held each time you take a sip
  • Double-wall vacuum insulation in both bottles for a condensation-free drinking experience
  • Both bottles have a carrying loop
  • The ThermoFlask model pictured above includes a removable silicone sleeve for protection against scratches, dents, and thuds when placing the bottle down
  • Both bottles have a powder coat finish, and the Hydro Flask has a lot more colors available
  •  Warranty:  Both bottles offer a lifetime warranty against manufacturer defects in materials and/or workmanship
Key Differences Summary
  • Hydro Flask has more size and color options
  • ThermoFlask offers standard straw and flip-top lids while Hydro Flask is a wide-mouth screw lid
  • ThermoFlask is 2-pack only and costs roughly 40 – 50% less than Hydro Flask
  • Hydro Flask is heavier

The big question is how do they perform? Why does the ThermoFlask cost considerably less? We answered these questions by performing a deep dive into the current reviews.

ThermoFlask vs Hydro Flask Reviews

After doing our deep dive into the current owner reviews for both bottles, we discovered several trends. When we review vacuum-insulated stainless steel water bottles, we look for rust, leak, and durability reports as well as temperature retention performance reports.

Here's what we found during our ThermoFlask vs Hydro Flask investigation:

  • We came across one interesting review written by a ThermoFlask owner who said the 24 oz size is perfect. The ThermoFlask owner said the 24 oz bottle is the perfect diameter and easier to grip.
  • The temperature retention comparison surprised us. Reviewers reported that both bottles perform the same, yet the ThermoFlask is significantly cheaper. We did find one experiment with hourly measurements for both bottles recorded during an 8-hour period. The Hydro Flask performed slightly better after 8 hours, and we give the nod to Hydro Flask in the temperature retention department (more on that below).
  • One ThermoFlask owner reported that condensation escapes through the lid while this does not happen with Hydro Flask bottles. This could explain why Hydro Flask does a better job of retaining temperatures.
  • We found just a couple of rust reports for the ThermoFlask while the Hydro Flask had a lot more. However, there are only a few hundred ThermoFlask reviews compared to thousands of Hydro Flask reviews. No stainless steel water bottle is perfect. They all have rust reports. The good news is Hydro Flask offers a lifetime warranty.
  • We found broken lid reports for the ThermoFlask and owners who are unhappy with the bottle’s ability to retain the temperature of hot beverages. One owner said temperature retention lasts 6 – 8 hours, not the advertised 12 hours.
  • Most of the negative Hydro Flask reviews are by owners who received dented bottles. Overall though, Hydro Flask has amazing reviews, more than 80% 5-star and just 6% one-star out of nearly 8,000 reviews.

Who wins?

In the battle of ThermoFlask vs Hydro Flask, who is the winner? The winner is...

Hydro Flask

Why is Hydro Flask the winner?

  • Hydro Flask has superior insulation, which makes it the clear winner in the temperature retention department. Here’s what we realized after reviewing the 8-hour test. Yes, the temperatures were only about 10 degrees different after 8 hours, but, temperature loss increases exponentially. If the same test had lasted 24 hours, the difference in temperatures would have been much greater.
  • Yes, you can save a good chunk of money by choosing ThermoFlask over Hydro Flask, and this could be the smart choice if you’re not concerned about temperature retention and keeping ice frozen for longer periods.
  • Another significant point to remember is the condensation leakage through the ThermoFlask lid reported by own owner. We don’t like that problem and prefer a complete seal all the way around. It can get annoying to unscrew the Hydro Flask lid every time to take a sip, but if that’s what it takes to get a proper seal, we’re cool with it.
  • The broken lid reports for the ThermoFlask were enough to turn us off. At first, we liked the convenience of the ThermoFlask lid, but not so much that we want to deal with the inconvenience of a broken or leaky lid.
  • Hydro Flask is a more reputable company and has been in the biz longer. When you buy from Hydro Flask, you’re buying from one of the top dogs in the water bottle industry. They have a lot more to spend on developing a better product than their imitators.
Bottom Line
Buy ThermoFlask if you don’t plan on using your bottle a lot and are unconcerned about temperature retention. The ThermoFlask does a satisfactory job of retaining temps and will get the job done when needed for occasional use. If you plan to use your bottle all day, every day, why not purchase a premium Hydro Flask that performs better?

Final Thoughts

Over the past month, we've reviewed a long and growing list of vacuum-insulated stainless steel water bottles. We have a handle on what makes the top brands better than their followers. It's the little design differences that make the big differences in the grand scheme of things.

Do you want a reliable insulated water bottle to use day in and day out? Do you want a bottle that'll keep your cold drinks cold the longest and the same with your hot beverages? Is keeping ice for long periods important to you? If you answered no, there's nothing wrong with buying imitators of the top brands. If you answered yes, choose a bottle that's more reliable and sold by a company with a long track record of success.

In the battle of ThermoFlask vs Hydro Flask, Hydro Flask is the better performer.

What did you think of our comparison? If there's anything you'd like us to add or we missed, we'd love to hear from you in the comments section.

We noticed that ThermoFlask is very similar to the Takeya insulated water bottle. We recommend our Takeya water bottle review if you’re still unsure about which bottle is the best for you.