10 Best Soft Flasks Tested

In a Hurry? Editors choice:
SLS3
Test Winner: SLS3
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Soft Flasks can be convenient, spacious and come in many different styles and sizes to fit your running needs. Whether it fits in a running belt or you just like to keep things tidy, you will find the best soft flasks can accommodate any lifestyle.

We all know how important staying hydrated can be and for athletes, even more so. Furthermore, reusable water bottles prevent extra plastic waste from continuing to take over the planet and we like the sound of that.

Scroll through and check out what we came up within our 10 Best Soft Flasks lineup. Our team spent hours researching to make sure we are offering the most current and best flasks available. You can check out our FAQ and Criteria section as well below to answer any additional questions on what makes the best soft flasks, helping you find one best suited for you.

Standout Picks

The SLS3 Soft Flask is extremely lightweight, adding minimal bulk to your running gear. The bite valve makes it easy to use while in motion, whether you are running, hiking, or training at the gym.
Amazon Link
Available in 4 colors, this soft flask is built with a wide mouth so you can put ice inside for extra cool refreshments.
Amazon Link
Nomader products were inspired by, you guessed it, nomads. Their gear, like the collapsible water bottle, was designed for people with on-the-go, active lifestyles that are outdoors or travel frequently. This durable soft flask stores conveniently making staying hydrated on a long run a breeze.
Amazon Link
Vapur Element is BPA free and can freeze without damage. This is a great option for those that prefer a cold beverage on the go and with their anti-bottle campaign, you’ll feel better about choosing to help the environment. That is the kind of soft flask we can get behind.
Amazon Link
This TPU collapsible soft flask conforms to any shape and keeps you hydrated on the go. The bite valve makes it a good choice for both regular workouts and races.
Amazon Link
Coming in many different fun prints, you can find a Platypus Duolock soft flask to fit your hydration and fashion needs. Their convenient design makes it easy to bring your hydration station with you without taking up space or adding weight to your workouts. This is a collapsible water bottle you will enjoy using.
Amazon Link
This soft flask is a big hit amongst runners- it can be filled both with water and gel. Like many other products on our list, it’s BPA free. Have a look at the newest version of this soft flask!
Amazon Link
The Katadyn BeFree is a unique soft flask because it has a built-in water filtration system so you can rehydrate anywhere your run takes you. Replacement filters are available to keep you using this flask for a long time.
Amazon Link
The Hydrapak Softflask Hydration Flask is a small and lightweight option for runners. It comfortably and easily can fit in a pocket or vest without adding weight that will hold you back during your runs.
Amazon Link
This soft flask compresses as you drink from it, instantly lessening the bulk to carry while you run. It is also one of the smallest flasks once fully compressed and folded.
Amazon Link

Criteria Used for Evaluation

Size

There is a wide range of sizes available on the market.

On the market, there’s a wide range of soft flasks products. They can be used by everybody but when it comes to runners, the size or the volume is really crucial. While taking part in a race you can’t stop to drink some water. This is why soft flasks were invented. You should personalize your product. There is a wide range of sizes available on the market. Bigger ones are best for those who are very thirsty during a race or a contest and they don't have a problem with taking something bigger. Those runners who aren't very interested in carrying soft flasks who are bigger than usual should choose the normal or a small version. The big problem that many runners encounter is that the producer offers only one size. This is a big inconvenience as it may small for well-built men and he would have to take 2 or 3 packages to slake his thirst. On the other side, runners who need only a few of this product, they may be discouraged by the fact that this is an additional burden during the race. When it comes to choosing the shape, we don't have a wide range of shapes. This is because the best shape that you can carry during the race is similar to a rectangle. However, you can always check the measurements of the product. Producers very often give the details about the width and length.  You may think that this is something that you shouldn't care about, usually soft flasks really fit you. However, you should check the measurements for one reason. If you want to carry your soft flask in your pocket, you must be aware that sometimes the product is too big. We would recommend checking the measurements of the pocket and of the product and it will give you more confidence. The volume is a very individual case. If you want to carry your soft flask with you, we would recommend purchasing 0.6 liters. It will make you feel hydrated and you won't carry too heavy. On the market, there are also available soft flask with 2 liters and it's perfect for cooling down after the race.

Water Resistance

Sometimes, you unintentionally squeeze the product too much and the gel or water starts to leak. This is because the cap isn't strong enough...

The big problem when purchasing a soft flask is finding the product which won’t be leaking. Even the most durable material or cap may not be enough. Even the best companies offer products that may have a problem with leaking. Sometimes, you unintentionally squeeze the product too much and the gel or water starts to leak. This is because the cap isn't strong enough to stay in place. However, buying a product which is harder to open isn’t the best idea. During the race, you may have problems with hydration as the snap lid may be very hard to open. Leaking of the product is a very common problem among the runners. The leakage of the water is not a very pleasant thing as you have all your suit wet, especially the trousers and it doesn't look good. Although the leakage of the water is really annoying, the leakage of the gel or any other substance is worse. This is because they have a different consistency and your whole pocket start to be sticky. What's more, the smell of the gel may be really terrible for some runners and that's why a solid package is needed. This is why many runners decide to purchase their product in a local store or that want to at least see the product and touch it. The best option is to check if the product is leakage-free and then you can purchase it online. Check if the cap is well made, it can't be a cheap, plastic one. You can even try to squeeze the product to see whether the problem happens. Remember that if you close the product not good enough, it is obvious that it will leak so it's not always the matter of the quality of the product.

Durability

A good test of the durability of the product is to check if after 2 or 3 usages it smells okay.

Good durability is a key to success. Always check how the product was made and don’t search for products with lower-class materials only because they’re cheaper. They are probable to last fewer months than those with normal prices.  A good test of the durability of the product is to check if after 2 or 3 usages it smells okay. If the products smell bad, it's obvious that this soft flask was made with very cheap material and we wouldn't recommend to use it anymore. Low-quality products aren't durable but many readers can't even check the durability because they throw them away much earlier. Why? Because some soft flasks, these poorly made, may change the taste of the water. This is something that is the most disgusting thing. Would you like to drink water with some chemicals in it? Checking if there is not any leakage while using the product is the best test for durability. As we've said before, it sometimes runner's fault because he or she won't close the cap good enough and there's a leakage. If you see that you have a leaking soft flask, you may be sure that your product won't be durable. Durability should be an important factor, you spend money on the product- you want the best quality. What you must remember is that you can't keep your one soft flask for years. After this time, your product won't be able to perform some functions that are essential to good hydration.

Features

Beyond being used as a package for liquid substance, you should consider the other aspects of soft flasks.

Let’s start with cleaning. Many buyers who buy this kind of product often complain about cleaning the product. It’s true because it’s not easy to clean and not every product can be washed in a dishwasher. Cleaning is an important part as it makes your device bacterial free. You should clean your device at least once a week or even more, it depends how much do you use it. It’s also a good idea to check if you can attach the product to your clothes. It may really make it easier to carry it, rather than wearing it in a pocket. It's very uneasy, especially during the race or marathon, to check your pockets for the soft flask. It's better to have it attached and you can run, observe the track and drink at the same time. Remember also that you need to read carefully the description of the product because not every package can be used with both liquid and gels. Sometimes you can pull the water only. This is is something that annoys many runners when they can't pull the liquid inside the tube. And if you want to fill the soft flask, you need to also make sure that it’s suitable for both hot and cold beverages. Pulling the hot water into the tube may really destroy it and we don't really recommend to take hot water with you for a marathon or race. It will get much hotter and you won't be able to drink it.

Value

Here comes the last main factor to evaluate but of course it is not the least important.

As we said before, it’s not worth to search for really cheap products as they are likely to leak and they’re not very durable. They also can have an impact on water taste and smell. From the other side, the best products aren’t always the most expensive ones. You should really carefully check the price as there are other volumes. This is a common mistake that people buy a product that is cheaper but they forget to check the volume. We have got on our list the product from less than 10 dollars to up to 30. This is because we want to present the products that are available not only for rich people or very professional runners. We want to provide products for those who can't spend too much on this kind of stuff but they still want to enjoy good quality. people often compare the prices in stores to those in online shops. The differences aren't big and you must remember that you must also pay for a delivery when you shop online. When it comes to soft flasks, we would really recommend investing your money. Most of these products are reusable and you can enjoy them for a very long time. It's a total must-have for marathon runners. We know that they are given the water during the race, but your own soft flask is a perfect idea as you can fill it with energizing gel and boost your performance. It's better to pay a bit higher price and enjoy the best quality.

10 Best Soft Flasks

1. SLS3

Where to buy
Amazon Link
SLS3
Amazon Link

The SLS3 Soft Flask is extremely lightweight, adding minimal bulk to your running gear. The bite valve makes it easy to use while in motion, whether you are running, hiking, or training at the gym.

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Volume
This flask holds 17 ounces. It holds cold liquids only.

Construction
This bottle is made of collapsible BPA-free material. Even with welded seams, it weighs only 28 grams. The bite valve helps keep air out, preventing the water from sloshing around inside the bottle while you run, eliminating the potential for distractions or gait disruptions.

Durability
Although this bottle is highly durable and leak-proof, users report that it may be too much so. The leak-proof cap is reported to be very difficult to open and close, so users recommend using a different bottle while racing. However, users also note that it is a great choice for people that throw their water bottle into their bag or purse because it definitely won't leak!

Value
This is a slightly below average priced soft flask.

Amazon Link

2. ITYYT

Where to buy
Amazon Link
ITYYT
Amazon Link

Available in 4 colors, this soft flask is built with a wide mouth so you can put ice inside for extra cool refreshments.

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Volume
This bottle holds 26 ounces. It can hold cold beverages with ice, or it can hold moderately warm drinks, up to 100 degrees.

Construction
FDA approved, BPA-free medical-grade silicone was used to construct the ITYYT Collapsible Water Bottle. It can withstand temperatures from -40 to 100 degrees, holding both cold and hot beverages. It is also capable of accommodating ice cubes for those runners that enjoy a freezing cold drink during their workout. After rolling up, this soft flask can be held securely with a strap.

Durability
Silicone is highly durable and can withstand being dropped on a run, thrown into your bag, or a cycle through the dishwasher. The lid seal and valve are leakproof, and the cap keeps out dust and debris. Some users report that the closure strap fell off after a few uses.

Value
This is an inexpensive soft flask.

Amazon Link

3. Nomader

Where to buy
Amazon Link
Nomader
Amazon Link

Nomader products were inspired by, you guessed it, nomads. Their gear, like the collapsible water bottle, was designed for people with on-the-go, active lifestyles that are outdoors or travel frequently. This durable soft flask stores conveniently making staying hydrated on a long run a breeze.

Read more

Volume
The Nomader Collapsible Water Bottle holds 22 ounces of water or another liquid. It can hold both hot and cold beverages.

Construction
The silicone construction of this soft flask is free of BPA, lead, PVC, phthalates, and other chemicals. It can hold hot or cold drinks and rolls up securely with an attached belt-style strap. This soft flask is available in 9 colors to match every taste, wardrobe, or set of travel gear.

Durability
The silicone construction of this soft flask is made to withstand wear and tear and can hold up to temperatures as low as -4 degrees Fahrenheit and as high as 248 degrees Fahrenheit. It is equipped with a removable heat protection sleeve. It is shatterproof and is safe for the dishwasher and freezer. The cap is leakproof because of its “twist and lock” design, also has an anti-germ spout cover.

Value
This is an averaged priced soft flask.

Amazon Link

4. Vapur Element

Where to buy
Amazon Link
Vapur Element
Vapur Element
Vapur Element
Vapur Element
Amazon Link

Vapur Element is BPA free and can freeze without damage. This is a great option for those that prefer a cold beverage on the go and with their anti-bottle campaign, you’ll feel better about choosing to help the environment. That is the kind of soft flask we can get behind.

Read more

Volume

You’ll get a couple of options to choose from in size and color. Vapur Element comes in .4L up to 1.5L. All colors do not come in all sizes so you will have to choose accordingly.

Construction

The easy to open tough-seal flip cap makes securing your soft flask without the worry of spillage. Vapur comes with a built-in carribeaner for easy carry, making it accessible from a backpack, belt loop, purse, etc. If you have a loop you can clip it right on.

They offer a wide-mouth opening for easier filling and pouring as well as making it easier to clean. Furthermore, that clip we mentioned keeps the soft flask rolled up when not in use. This fits right in any standard pocket, offering convenient and compact carry.

Durability

Priding themselves on their Anti-Bottle design, they present Vapur Element as a foldable, rollable, storable solution to the ever-growing plastic bottle problem. Therefore, Vapur made the Element Soft Flask extra durable.

The freezing capabilities alone prove some of the durability. This soft flask is designed to take the added pressure of frozen liquids. They expand and even water bottle tend to burst open if you throw them in the freezer.

Vapur Element is made with a 3-ply BPA-free and dishwasher safe material. You’ll be able to keep it clean without the hassle or worry of the bottle falling apart.

Value

This is one of the most budget-friendly designed soft flasks we have on our 10 Best Soft Flasks lineup. It also offers the freezing option, which is something not common in most soft flask. This says something about the durability as well.

Amazon Link

5. Ultimate Direction Bottle with Kicker Valve

Where to buy
Amazon Link
Ultimate Direction Bottle with Kicker Valve
Amazon Link

This TPU collapsible soft flask conforms to any shape and keeps you hydrated on the go. The bite valve makes it a good choice for both regular workouts and races.

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Volume
This soft flask holds 14 ounces. It is suitable for cold liquids only.

Construction
This soft flask is made of TPU. It is clear so you can easily see how much liquid is left in the bottle, keeping you aware of when it is time to fill up. The nozzle is a high flow bite valve, so getting a swig of water on your run is quick and easy. This feature is especially convenient while racing. Users noted that the fill head is very small, making filling this flask a difficult, messy task.

Durability
TPU is a highly durable material and is dishwasher safe. It is also designed to be a flask that can be used day in and day out with worry.

Value:
This is an average priced soft flask.

Amazon Link

6. Platypus Duolock

Where to buy
Amazon Link
Platypus Duolock
Amazon Link

Coming in many different fun prints, you can find a Platypus Duolock soft flask to fit your hydration and fashion needs. Their convenient design makes it easy to bring your hydration station with you without taking up space or adding weight to your workouts. This is a collapsible water bottle you will enjoy using.

Read more

Volume

Platypus DuoLock soft flasks come in a couple of different sizes depending on preference. Each .75, 1.0, and the 2.0-liter soft flask is easy to carry and super light. They also are engineered with wider mouths to make filling and drinking easier.

Construction

With an easy to carry gate clip, you can wear it when its full and once it is empty, just roll it up and stick it in a pocket for easy carry. Furthermore, you won't taste anything but your beverage.

Each Platypus design is made BPA, Phthalate, and PBPS free. You can continue on your work out without worrying about chemical interference when you are hydrating. Moreover, the wide mouth and ergonomic design make it pleasant and easy to hold, dring and pour from.

Duolock design built into the mouth also offers a secure seal when there is water or other sports drinks in it. You won’t have to stress about it spilling on your belongings or squirting you during your run.

Durability

Due to the ergonomic design and wide mouth, cleaning it is super easy. IT is also dishwasher safe. The bottle is made to roll up, fill up, collapse and stretch. IT has to have some durability to be used over time.

They made it easy to clean, which also extends the lifespan. They won't be any unpleasant mildew or mold build-up that can render a water bottle pretty much useless and not to mention gross.

Value

Platypus Duolock is a super durable, convenient and affordable soft flask. Whether you’re on a budget or not, you won't have to dish out much to keep yourself hydrated. Furthermore, it doesn't have any chemicals and smells other bottles tend to have.

Amazon Link

7. Hydrapak SF500 SoftFlask

Where to buy
Amazon Link
Hydrapak SF500 SoftFlask
Amazon Link

This soft flask is a big hit amongst runners- it can be filled both with water and gel. Like many other products on our list, it’s BPA free. Have a look at the newest version of this soft flask!

Read more

Volume
There are two different sizes that you can choose from- 250 ml and 500 ml.

Construction
This Hydrapak SoftFlask was made with TPU. This material makes this product much more durable and it also provides a lot of flexibility. The top can be easily removed which makes cleaning much more easier. It is very easy to carry as there’s special finger loop and you can store it without problems. You get a lot of fluid when you squeeze even a little bit.

Durability
The TPU construction and welded seams make this bottle extremely durable against wear and tear and leaks.

Value
Some of you may think that this is a real bargain but you must be aware that the size isn’t also big so we could say it’s an average price.

Amazon Link

8. Katadyn BeFree Water Filtration System

Where to buy
Amazon Link
Katadyn BeFree Water Filtration System
Amazon Link

The Katadyn BeFree is a unique soft flask because it has a built-in water filtration system so you can rehydrate anywhere your run takes you. Replacement filters are available to keep you using this flask for a long time.

Read more

Volume
The Katadyn BeFree Water Filtration System holds 20 ounces of water. Water is the only liquid that should be used it this flask.

Construction
This collapsible soft flask is equipped with a .1 micron water filter, which can remove potential harms from your drinking water, including Giardia and Cryptosporidium. It has an EZ-Clean Membrane which tidies up with just a slosh of water.

Durability
The flask portion of this bottle is highly durable, but users have some reservations about the filter. The advise being extra gentle with it, as the small components can be damaged really easily. Replacement filters are available for purchase from Katadyn.

Value
This is a high priced soft flask. The high price is a result of the filtration system that is built into the bottle.

Amazon Link

9. Hydrapak Softflask Hydration Flask

Where to buy
Amazon Link
Hydrapak Softflask Hydration Flask
Amazon Link

The Hydrapak Softflask Hydration Flask is a small and lightweight option for runners. It comfortably and easily can fit in a pocket or vest without adding weight that will hold you back during your runs.

Read more

Volume
This flask can hold 250mL of water or your electrolyte drink as well as 8 servings of energy gels.

Construction
This is a TPU, HDPE, and Silicone soft flask. It is BPA and PVC free as well as dishwasher safe.

Durability
Highly durable and easy to carry. Not easily breakable.

Value
Highly affordable.

Amazon Link

10. Salomon

Where to buy
Amazon Link
Salomon
Amazon Link

This soft flask compresses as you drink from it, instantly lessening the bulk to carry while you run. It is also one of the smallest flasks once fully compressed and folded.

Read more

Volume
This flask holds 8 ounces of liquid. It is only suitable for cold liquids.

Construction
The Salomon Soft Flask is made of PVC-Free TPU. It can be folded small enough to fit in the palm of your hand but has no closing strap or fastener to attach it to your outfit. Users report this bottle has an odd smell that never goes away. As a result, some users purchased a replacement flask after just a short time.

Durability
TPU is an extremely durable material, so this soft flask can stand up to bumps and drops. Some users report leakage after only a short period of use.

Value
This is an average priced soft flask.

Amazon Link

Sources

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Inside RunnerClick Pro, runners of all strengths come together to meet and support one another, get answers to burning questions, learn from experts, participate in personal challenges, and more.