A backpacking water filter is a key essential for any multi-day outdoor adventure

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Why is a water filter so important? Parasites and viruses live in the lakes and rivers that you rely on to stay hydrated in the backcountry. Giardia is the most common and can cause abdominal cramping, nausea, diarrhea,  and vomiting – not exactly what you had planned for your next adventure, right?  

Some argue that you don’t always need to filter water where streams are fed by fresh snow-melt, but keep in mind that if livestock, wildlife, or humans can reach an area, so can contaminants that are transferred via fecal matter.

In this roundup of the best backpacking water filters, we’ll walk you through the key factors to consider when choosing one and share our favorite recommendations for your next adventure, whether it’s a quick weekend backpacking trip, a car camping expedition or a long-distance thru-hike! 

Here are the best backpacking water filters and tips for how to choose the right purification system for your adventures.

Types of Water Filters for Backpacking

Gravity Water Filter

Gravity filters filter water by using gravity–there is no squeeze or pumping necessary. They generally consist of a bag with a hanging mechanism that you fill with the water you want to filter, a filter, and a long tube that can be used to fill whatever container you’d like. Simply fill the bag from the water source, hang it up, and gravity carries water down through the filter and into a new container. Challenges for gravity water filters can be filling the bag from shallow water sources and finding a place to hang it.

Squeeze Water Filter

Squeeze water filters require manual effort to squeeze water through the filter. These types of filters need to be back flushed more often than other filters to prevent clogging which reduces the flow rate and makes it harder to squeeze water through. Back flushing is how you clean the filter and this is done by using a syringe to shoot water through the filter in the opposite direction that water filtration takes place. Most squeeze water filters come with a syringe cleaning system to make this process simple.

Pump Water Filter

Pump water filters require manual effort to pump water through the filter. Most water filter pumps come with two hoses, one that you drop into the body of water you want to filter from and one that transfers the filtered water into your water container of choice. These types of water filters are versatile because they can filter from shallow running water and the filter itself is replaceable, but they do require you to sit alongside the water source and pump.

UV Light Water Purifiers

Pen style UV light water purifiers use UV light to treat water. You basically fill a container with water and swirl the pen around until the UV light turns off which usually takes a minute or so. They’re lightweight, super easy to use, don’t clog or need to be replaced, and they can easily treat water for a large group. They also virtually eliminate viruses in addition to bacteria and protozoa while most water filters do not eliminate viruses. The downside to UV light water purifiers is that they don’t filter out sediment and they require batteries or a charge to work.

Water Filtration Bottles

Water filtration bottles have a built in filter. You basically fill the bottle with water and the water is either filtered as you sip through the filter or pressed through the filter like a coffee press. They’re very easy to use and provide a method of filtering and drinking all in one bottle. However the amount of water you can filter and carry is constrained by the size of the bottle.

Purification Tablets

Water purification tablets virtually eliminate bacteria, most protozoa, and viruses from water whereas most water filters do not remove viruses. They are very easy to use: Simply drop them into the water you gathered to treat, follow the instructions, and wait. The downside is that they do contain chemicals, can leave a bit of an iodine taste, and they’re not recommended for pregnant women or people with thyroid conditions. However, it’s always good to have a few of these on hand in case your primary filtration method breaks or in case you need them in a pinch while traveling.

The Best Backpacking Water Filters & Purification Systems

Here are some of the best backpacking water filters out there including a few of our personal favorites. 

Platypus GravityWorks Filter System

The Platypus GravityWorks Filter is a gravity filter (as the name implies) and can filter 1.5 liters per minute. The great thing about it is that it only includes one 2L bag, which you can use to filter water into any container you’d like, such as a Nalgene, CamelBak, hydration reservoir, cooking pot, etc. You basically just fill it up, hang it, and let gravity do the rest!

Check out our detailed review and video of the Platypus 2L Gravity Filter when Kristen used it in Zion National Park. This is also the filter Kristen used on the John Muir Trail, although she only used the dirty bag and filtered it into a super lightweight Platypus Soft Bottle.

Check Price: Backcountry / REI / Moosejaw

Weight: 9.5 oz

Filter Rate: Up to 1.5L per minute

Effectiveness: Eliminates bacteria, protozoa, and sediment. Does not eliminate viruses.

Great For: Backpacking trips, groups, setting up a fixed campsite in the backcountry for a few days, or car camping where there is no potable water available

Looking for a bigger option? Snag the Platypus 4L system or 6L system for group or family trips into the backcountry!

Katadyn Gravity BeFree Water Filtration System

Similar to the Platypus water filtration system above, the Katadyn Gravity BeFree uses gravity to make filtration easy. The system comes with a bag that you fill with the water you want to filter, then you hang it up and use the output hose to fill your water bottle, hydration pack, or any other container. It filters up to 2 liters per minute and there’s no need to back filter, squeeze, or do any other manual work.

Check Price: Katadyn / Backcountry / REI

Weight: 6.8 oz

Filter Rate: Up to 2L per minute



LifeStraw Flex 2-Stage Multi-Function Water Filter System

The LifeStraw Flex Multi-Function Water Filter is great because it’s very versatile. You can use it as a straw filter to drink directly from a water source, as a filtration bottle by simply drinking out of the bottle, as an inline filter on your hydration reservoir, or as a gravity filter. The threads on the filter also allow it to be screwed onto nearly any disposable water bottle (but you’re not using those anymore, right?). Plus, for each LifeStraw purchased, 1 child in a developing community receives safe drinking water for an entire school year – how cool is that?

Check Price: REI

Weight: 1.7 oz.


Great For: Backpacking trips, trail runs, and day hikes

Katadyn BeFree Water Filtration System

Having won the Runner’s World “Gear of the Year Award,” we definitely want to give a nod to this great lightweight 1L Katadyn BeFree Collapsible Water Filter Bottle. Filtering up to 2 liters of water per minute, it’s pretty speedy for a short weekend trip or a long day hike.

The filter sits inside the water bottle, so all you do is fill it up and go. As you drink, the water gets sucked up through the filter.

The bottle is also collapsible when it’s empty, making for easy packing or you can even carry it on a hip belt!

Check Price: Katadyn / Backcountry / REI

Weight: 2.3 oz

Filter Rate: Up to 2L per minute


Great For: Trail runs, day hikes, and short backpacking trips where water is abundantly available

Sawyer Mini Water Filter

The Sawyer Mini is one of the smallest and lightest water filters out there weighing in at only 2 ounces. However, it does take a substantial amount of time to filter multiple liters and requires some manual effort in squeezing the water through the filter.

You can use the Sawyer Mini to drink directly from a stream like a straw or you can stick it into whatever water bottle you want and start sipping through the top of the filter.

Kim started the PCT with this water filter option but quickly upgraded to the Sawyer Squeeze after only 1 month because it wasn’t as quick or efficient as she needed. That being said, it’s still a great budget-friendly filter for short backpacking trips and long day hikes.

Check Price: REI / Moosejaw

Weight: 2 oz


Great For: Long day hikes, short backpacking trips

Sawyer Squeeze

The Sawyer Squeeze is a step up from the Sawyer Mini but it still requires some manual power. This was the only con that Kim found with this product while using it for 4 months on the PCT.

It works by filling up the included water pouch in a lake or stream, screwing on the filter to the top, and then squeezing the pouch to push water through the filter and into your mouth. The Squeeze can also be rigged into a neat do-it-yourself gravity filter.

The filter inside the Sawyer Squeeze is ceramic which means it can freeze. A quick fix to prevent this is to put it with you in your sleeping bag at night.

Check Price: REI

Weight: 3 oz

Filter Rate: Up to 1.7L per minute


Great For: Long day hikes, backpacking trips, thru-hiking

SteriPEN Ultra

The SteriPEN Ultra uses ultraviolet rays to purify up to 32 oz in 90 seconds. It’s great as long as your water source is clear and free of debris! SteriPENs are especially good for international travel.

To purify water with a SteriPEN, you fill up your water bottle, swirl the SteriPEN around for 90 seconds, and the water is ready to drink. During Kristen’s Anywhere Plus trek in Nepal, her guide had 2 SteriPENs and was able to quickly purify water for the entire group of 11 people during breakfast.

The SteriPEN classic takes batteries, while the SteriPEN Ultra is rechargeable with a USB cord so it can run off an external battery charger or a solar panel.

SteriPEN also makes an option that is an ounce lighter, called the Adventurer but it requires lithium batteries which can be expensive and you’ll need to carry backup batteries to be safe.

Check Price: Backcountry / REI / Campsaver

Weight: 4.9 oz with batteries

Treatment Rate: 32 fluid oz per 90 seconds

Effectiveness: Eliminates bacteria, viruses, and protozoa. Does not filter out sediment.

Great For: International travel

Grayl Ultralight Compact Water Purifier Bottle

The Grayl Ultralight Water Purifier Bottle is unique in that it filters out both bacteria and protozoa and eliminates viruses. Most filters only filter out bacteria and require a purification step such as tablets, drops, or a SteriPEN to kill viruses. So if you want a filter that does it all, this is a great companion. The filter is also replaceable and is good for up to 300 cycles. While this may not be the lightest water filter for backpacking, it’s great for long day hikes and other adventures where there’s ample water, especially in countries where viruses may be present.

Check price: GRAYL / Backcountry / REI

Weight: 10.9 oz

Filter Rate: Up to 16 fl oz per 15 seconds or 2L per minute

Effectiveness: Filters out bacteria, protozoa, and sediment and eliminates viruses

Good for: Day hikes or short backpacking trips where water is abundant, international travel

MSR MiniWorks EX Water Filter

The MRS MiniWorks Ex Water Filter is great hand pump filter that has a ceramic/carbon filter to remove bacteria and protozoa. It filters water at 1 liter per minute and the bottom can easily screw onto a Nalgene for easy operation. It also comes with a cleaning kit for easy cleaning in the field.

Check price: Backcountry / REI / Moosejaw / Campsaver

Weight: 14.6 oz.

Filter Rate: Up to 1L per minute


Good for: Day hikes, backpacking, car camping

Katadyn Micropur Purification Tablets

With water purification systems like the Katadyn Micropur Purification Tablets it’s 3 simple steps: 1) Collect water, 2) Add purification tablets or drops, and 3) Wait

Generally, you have to wait anywhere from 15 minutes to 4 hours before consuming the water. Keep in mind that drops and tablets only work well for clear water sources and you also have to make a personal decision about the chemicals you ingest using these tablets.

Check Price: Backcountry / REI / Moosejaw / Campsaver

Weight: 0.9 oz

Filter Rate: 15 minutes to 4 hours depending on quality of water

Effectiveness: Eliminates bacteria, viruses, cysts, and giardia. Does not filter out sediment

Great For: Short backpacking trips, back-up water purification method, car emergency kit, natural disaster home preparation kit

How to Choose a Backpacking Water Filter

1. Purification vs. Filtration

Let’s start here because it’s super important to know the difference. The difference between a water filter and a water purifier is the size of the microorganism each fight. 

Purification eliminates viruses while filtration removes bacteria, protozoa, and sediment.

Bacteria in water sources is a concern within the USA and Canada, while protection from waterborne viruses is more important for international travel.

Filtration also removes sediment and silt, making the water more pleasant to drink while purification does not.

2. Weight

Weight is an important factor to consider for all of your backpacking gear and water filters are no exception, especially on a long-distance trip. While not always the case, there tends to be a tradeoff between weight and speed of filtering. The smaller and lighter the filter, generally the longer the filtration process.

3. Filtration or Purification Speed

How patient are you? Some filters are speedy, while others take quite a bit of time. It’s also important to consider how many people you will potentially be filtering water for since more people means more water and more time.

Using chemicals, such as chlorine or iodine to purify water can take up to 4 hours while other filters can do the job within minutes. If you are on any kind of backpacking trip, whether just a quick weekend trip or a thru-hike of a long-distance trail, time is of the essence–remember you came to explore the outdoors and you will not want a treatment method that takes a long time!

4. Type of Backpacking Water Filter

As we covered in the beginning of this post, some filters require a simple set-up and then allow you to sit back and relax while your water is filtered. For example, gravity filters work by using gravity to filter water from one bag to another.

Other filters require active participation–meaning you have to physically filter the water usually by either squeezing or pumping it through the filter.

It’s important to also consider that some backpacking water filters are ceramic and cannot be exposed to extremely cold temperatures.

5. Cleanliness of Water Source

Different elements can murk up water in varying ways such as glacial sediment, leaf debris, and/or mud stirred up by a recent rainstorm. If you plan to use a SteriPEN or chemicals you’ll also need to bring something to act as a filter to help you remove dirt and debris prior to filtering.

Depending on how congested the water is sometimes a simple bandana can act as a pre-filter.

Do you have a favorite backpacking water filter or purification system? What has worked best for you? What questions do you have? Leave a comment below!

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The post The Best Backpacking Water Filters of 2020 appeared first on Bearfoot Theory.

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