Best Backpacking Water Filter of 2021

Best Overall for Small Group Use

Platypus GravityWorks

Effective against: Particulates, Bacteria, Protozoa | Weight: 11.5 oz

The Platypus GravityWorks is our favorite gravity backpacking water filter that quite literally does it all. It's fast and portable while remaining easy to use. Setup is quick, and since it can supply 4 liters of filtered water at a time, it works well for personal use but really excels for a small group. It features two durable bags marked as "clean" and "dirty" in addition to a high-flow filter that is compatible with water bottles and hydration bladders. The bags can easily be converted into a solar shower or handwashing station to make your base camp complete. We love that we can simply hang it up with dirty water, walk away, and enjoy effort-free (no pumping, no squeezing, barely any waiting) filtered water within minutes.

Unfortunately, this system does not treat viruses, and the bags can be hard to close in cold weather. The attachments used to hang the bag look less durable than other options, yet we have had no issues after several backcountry trips with this filter. Also, like any gravity filter that uses an in-line filter, it'll slow down if exposed to water with high amounts of sediment and will need to be cleared. That said, if you're seeking a stellar gravity filter, this is our recommendation for its durable architecture and high rate of flow.

Read Review: Platypus GravityWorks

Best Overall for Personal Use

Sawyer Squeeze

Effective against: Particulates, Bacteria, Protozoa | Weight: 5.7 oz

The Sawyer Squeeze is one of the most time-tested, on-the-go filtration systems. This lightweight option is wonderful for personal use, providing great functionality on multi-day excursions and daily adventures into the backcountry. Of the multiple Sawyer Squeeze systems, this offers the fastest flow rate, filtering one liter of water in just 40 seconds in our tests. It's also packable, easily fitting into a running pack or pocket. Use it as a squeeze-filter with its accompanying bags or in-line with a hydration bladder. You can even screw it to the top of a compatible water bottle and drink directly from puddles with its complementary straw. Few contenders offer this level of versatility and portability, making it our favorite for personal use.

In our three years of experience, the provided filtration bags have typically broken after just three to four trips, at which point they require replacement. When we use it, we use it with a Platypus Hydration Bladder, as this burly bag doesn't break when squeezed repeatedly in our experience. We also notice that bringing the syringe for cleaning is a must to ensure the flow rate stays fast, otherwise, it'll slow down after just a few filtrations. It also comes with small parts, which are easy to lose. If you're heading out on a big adventure, buy a compatible and stronger bag to ensure reliable use for longer trips. For day trips, it's our go-to and top recommendation for individual use.

Read Review: Sawyer Squeeze

Best Bang for Your Buck

Katadyn Gravity Camp 6L

Effective against: Particulates, Bacteria, Protozoa | Weight: 11.7 oz

The Katadyn GravityWorks is a gravity-style backpacking water filter that stands out for its easy to use design and fast flow rate. It treats vast quantities of water in minutes without requiring pumping or work, making it an excellent option for a small group or solo use. Filling it is easy. The bag has a large opening and can easily be used to collect large amounts of water from rivers, lakes, and streams. Gravity will pull water through the filter as you set up camp or cook dinner, provided you have a high point to suspend it from. It's also compatible with most hydration bladder systems and can double as a handwash station or shower. We especially like the bag's fabric design that has proven to be quite durable over our four years of use, adding to its value in our eyes.

Unlike other gravity filters in this review, it does not come with an additional storage bag for clean water. Also, the placement of the filter inside the bag limits versatility. Since it sits at the bottom of the bag (as opposed to in the tubing line), it requires a branch or structure that can support its weight. In desert or tundra ecosystems, this can be a problem. Second, if the water source is turbid, it might clog quickly after just a few minutes, as it did in our experience. The third is difficulty in cleaning; the filter can't be back washed easily and instead needs to be rinsed. If clean water isn't available, you are left with an unusable filter. Overall, this gravity filter is best for relatively clear water sources where you can hang it high. It's quick, durable, and easy to use at a great price.

Read Review: Katadyn Gravity Camp 6L

Best Collapsible Bottle Filter

Katadyn BeFree

Effective against: Particulates, bacteria, and protozoa | Weight: 2.1 oz

Are you going out for a long day in the hills? The Katadyn BeFree is a personal soft hand bottle with a high flow filter in a collapsible, packable bottle. Scoop water on-the-go and drink straight from it. It'll filter as you drink, fueled by a soft squeeze and your sucking force. The soft bottle top is adaptable to other narrow bottle tops, making it reusable if your bag happens to spring a leak. In the field, the short filter and collapsible bottle rolls up to the size of your palm and is easily packable. For ultra-distance adventures where you might already be using a soft bottle, this filtration system is simply awesome and can't be beaten for its functionality.

The biggest issue with this product is the durability of the soft bottle. We have had this bottle spring leaks on us pretty consistently over the last five testing periods. However, since the filter itself is adaptable to other bottles, it can be used over and over again. It also only holds 0.6 L of water and can't be used for large storage, so water sources need to be plentiful. Use this system if you're seeking a super lightweight filtration option that boasts a high flow rate and a soft, packable bottle.

Read Review: Katadyn BeFree

Best Chemical Treatment

Aquamira Water Treatment Drops

Effective against: Bacteria, protozoa, and viruses | Weight: 3.0 oz

If you've got time to wait for your potable water, the Aquamira Water Treatment Drops is a lightweight and inexpensive travel system used by many thru-hikers. Treatment is simple: activate the substances, then drop them into your water and wait. Of all the chemical treatment systems, it kills the most stuff, including finicky cryptosporidium cysts. When doubled with a filtration system, it can easily be used anywhere in the world. Plus, it's inexpensive, incredibly packable, and very reliable.

Unfortunately, chemical treatment doesn't filter out particulates, so we'd recommend carrying a pre-filter or a handkerchief to do that work. While it's advertised that treatment time is just 15 minutes, which will kill most stuff, you have to wait much longer (four hours is recommended) to get rid of hard-shelled cryptosporidium cysts, a protozoan found in North America. These drops are our favorite chemical treatment for backcountry water for their packable design and ease of use. Just make sure you have time to wait for your sterilization.

Read Review: Aquamira Water Treatment Drops

Best UV Bottle Purification System

CrazyCap 17oz

Effective against: Viruses, bacteria, protozoa | Weight: 12.6 oz

The CrazyCap uses UV light to sterilize surfaces from viruses, bacteria, and protozoa. It uses a USB charge cable to charge up this bottle cap (that is compatible with some other bottles), so maintenance is easy. Simply press on the top twice to purify the water you've collected in the bottle, and get 0.5 liters in just 60 seconds. The cap based system makes it versatile, and it can easily be used while hiking, traveling abroad, or around the house.

While this system is quite nice, we've got to say it's hard to trust that a UV light is actually working to destroy viruses. It almost seems magical and takes some trust. Aside from that, this is not a filtration system, so don't expect it to get rid of particulates in the water. It also doesn't protect from chemicals, pesticides, or heavy metals, so don't go scooping up water where these could be present. This self-contained UV light water purifier is super convenient and an option we'd recommend considering for international travel or where a clear water source might contain a virus.

Read Review: CrazyCap 17oz

Excellent for Turbid Water

MSR Guardian Purifier

Effective against: Viruses, particulates, bacteria, protozoa | Weight: 1 lb 4.5 oz

The MSR Guardian stands out for its exceptional ability to purify water of water-borne viruses, unlike other hand pumps on the market. The hollow fiber filter has a massive expected lifespan (which presents a great value), and there's no need for maintenance. It's built to last, it's tough, it's strong. We've owned one for over seven years, and it's done great work for us traveling in international countries and hiking in the backcountry. Its flow rate is exceptional for a pump filter (about 37 seconds for one liter), while the backflush system makes it functional even in the sludgiest of stagnant or turbid water holes. The filter is resilient to freezing, making it an option to consider for trips in colder climates. It's also the only system that actually performed remarkably well in turbid water due to its built-in backflushing system. If you encounter water muddied with sediment, this is the one we reach for.

While this purification system is quite incredible, it's not for everybody. The initial price tag is immense, and quite frankly, most people aren't willing to pay it. If you're looking for a pump filter that'll do work here in North America, you probably don't need this Cadillac of hand pumps; a normal hand pump will do. This model is rather large, which takes up space and will add to your pack weight. If you need a purifier for international travel or one that sports a backflush system for turbid water, this is one sports reliability that's worth the initial investment.

Read Review: MSR Guardian Purifier

Large Capacity for Groups or Basecamps

MSR AutoFlow XL

Effective against: Particulates, bacteria, and protozoa | Weight: 16.2 oz

The MSR Autoflow XL is a gravity backpacking water filter designed for large group use and basecamps. Its large capacity can hold up to 10L of water, with an adaptable design fitting many different storage vessels. This is our favorite for group use because it requires minimal setup and can be left unattended while filtering large quantities of water. It also doubles as a handwash station or even a shower during the warmer seasons.

While we do love this system, it offers the slowest flow of any gravity filter tested. The filter needs consistent backflushes, especially when dealing with turbid water. If you need to use its whole capacity, site selection can be limited by the availability of strong anchors to hang this model from. If you require a gravity filter that'll filter large quantities of water, this is a good choice.

Read Review: MSR Autoflow XL

Top Value Hand Pump

Katadyn Hiker

Effective against: Particulates, Bacteria, Protozoa | Weight: 15.2 oz

The Katadyn Hiker is a reliable pump filter that's one of the best selling on the market. The pump-action system collects water while you actively pump it through the device into your water bottle. It works best with a wide-mouthed container (i.e., Nalgene bottle) and also has a hydration bladder compatible attachment so you can fill up hydration bladders with ease. This mid-range pump is fast, smooth, and easy to use. It's one of the most consistent in its performance, offered at a great price.

Unfortunately, this pump can't easily be cleaned if it gets completely clogged. The filter also absorbs water and cannot be subject to freezing, which limits its use in cold weather. If you're looking for a hand pump, this one is most likely to get the job done, in the right environments, while saving you a chunk of change.

Read Review: Katadyn Hiker

Best Bottle Press Purifier

Grayl Geopress

Effective against: Particulates, Bacteria, Protozoa, Viruses, Chemicals, Heavy Metals | Weight: 19.4 oz

The Grayl Geopress quickly turned into one of our most used and favorite purification systems. In comparison to the rest, it supersedes most systems for a variety of reasons. It's easy to collect water, push it through, and drink right away. More importantly, it removes the most disgusting water contaminants that you would find. Not only including viruses, but it's said to remove heavy metals, plastics, pesticides, and more. When we tested this in a heavy metal polluted river in Ouray, CO, our water came out clear. No other system could purify this well, leaving some coloration or smells behind. The bottle is very durable, with the ability to travel well. Save yourself from buying tons of water bottles when you travel and get this instead.

Compared to the Grayl Ultralight system, this bottle is much easier to push down to force the water through the filter, especially with the handgrips along the side. While we appreciate the use of this system, it's also not our first choice for lightweight travel in the backcountry because of its bulky and heavier design. The cartridge life is minimal, and refills are pretty expensive. Based on these cons and our comparisons, we find this product provides relatively low value for the price. But for traveling, especially in urban areas abroad, we think it offers peace of mind when collecting water from taps or other polluted sources.

Read Review: Grayl Geopress

Why You Should Trust Us

Jessica Haist and Amber King are seasoned gear testers (over 15 years of collective experience) that love to explore in the backcountry. Both work in outdoor education. As educators, they spend lots of time in the woods, backpacking along trails, and exploring remote locations. You can find Jessica playing at the local granite crags, sucking up rays of the sun, or riding trails on her mountain bike. Amber is an avid ultrarunner and rock climber. She currently runs and owns a non-profit that takes kids into the backcountry daily. She also spends most of her free time trail running and backpacking through remote and high mountains. Our testing team uses these filters throughout all seasons of the year, with several years of cumulative experience testing these filters and purifiers.

To test each product, we take to the trails. We run, hike, and bike hundreds of remote trail miles with filters in tow, guzzling gallons of water filtered and purified from some pretty questionable sources. Using a systematic test plan, we assess each system's anatomy, dissect the pros and cons, and evaluate whether a system is reliable enough to earn our favor. Each product sees hands-on and in-field experience. We also perform rigorous indoor tests to determine minute differences between products. Specifically making sludgy water samples using fertilizers, soils, and other particulates to truly test how each filter and purifier performs. Our recommendations come from experience in the field and home-based experiments that comparatively test each product's performance.

Related: How We Tested Backpacking Water Treatments

Analysis and Test Results

This review features a wide range of water filters and purification systems. We explore options from simple tablets to complex purification systems with a focus on backcountry and international use. To rate each product, we consider six important metrics, including water quality, maintenance, treatment time, portability, ease of setup, and ease of filtration. While some products are like comparing apples to oranges, we use this rating to help you find a product that best fits your specific hydration needs, depending on where you travel or adventure.

Related: Buying Advice for Backpacking Water Treatments

Value

A great purifier or filter is one that lasts a long time and doesn't cost an arm and a leg to maintain. While the original ticket price on some items might seem really low, the expenses of replacement pieces might add up, running up a larger bill in the long run. To take a critical look at value, we took the time to calculate the cost per 100L of water for each filtration system. We also look at the price per 100 liters for the refillable filter cartridge. By looking at this data, you can see which systems offer the best upfront and long-term value. Of all these systems, the Sawyer Squeeze systems and CrazyCap offer excellent value. Both offer more filtered or purified liters before needing replacement than other models we tested.

The Katadyn Gravity Camp is a gravity filter that provides a great option for larger groups at a lower upfront cost and a reduced maintenance fee. The Katadyn Hiker Microfilter is a pump filter with a low upfront cost and great reliability and longevity for the single hiker. Both models are affordable and have different needs in mind. While purification tablets and liquids like the Potable Aqua Drinking Water Germicidal Tablets and Aquamira Water Treatment Drops have a super low upfront cost, they actually offer a lesser value per liter as they need to be replaced every 30 liters or so. When considering the price, consider how you'd like to pay for your system—either with small, repetitive costs or a larger sum but much less frequently.

Water Quality

When considering this metric, we specifically look at what the backpacking water filters can get rid of and the overall taste or odor of the water. We went to shallow puddles, smelly swamps, and pristine streams to see what each could do. Those that remove everything, including heavy metals and pesticides, triumphed in this category.

Backpacking water filters and purifiers use different types of technology to remove viruses in addition to protists, bacteria, and other water-borne pathogens. Filters typically don't have a pore size that can remove viruses. Other categories are chemical tablets and UV light systems. Below, we outline the different types of purifiers and filters out there and what they can eliminate.

Water Purifiers

Water purifiers are what you need if you're traveling abroad or treading in terribly polluted areas. Water purifiers remove particulates, protists, and bacteria, but can also rid the water of viruses. For example, the MSR Guardian is a tried and tested hand pump purifier that can do just that. It can expunge smells from water and remove viruses, but it can't remove heavy metals or chemicals from water sources. That said, if you're traveling internationally, it's a great companion to pump water from the sink or collect from a local stream.

The Grayl Geopress stands out above the rest because this water bottle purification system uses push technology to scrub water of everything that might contaminate it. We tried this on a particularly contaminated stream in Ouray, Colorado, that runs yellow from pollutants like lead, arsenic, chromium, and iron oxides. The water smells acidic, and is acidic. After using the purifier, it took all these metals out and neutralized the pH of the water, which amazed our testers. We drank it shortly after, not noting any weird tastes or side-effects. The Grayl Ultralight provides the same level of water quality as well but is much more of a pain to use. This is a filter we'd trust taking water from any source, whether you're traveling to Africa, Thailand, India, or anywhere abroad. We'd also take the MSR Guardian with us, but we'd be more careful about where we get our water from. That said, the MSR Guardian has a much longer lifespan and can process more water in bulk, where the Grayl can only process 750mL at a time.

The Aquamira Frontier Max is a unique in-line purification system that removes viruses and other contaminates. It can be attached to a hydration bladder hose, gravity filter, or used on its own to provide water purification. So instead of filtering your water and drinking it, you suck it through the filter. It also has the ability to remove all the substances that you can think of. A good option if you don't like to pump or press water. The only issue is it takes quite a bit of sucking power.

UV Light

UV light purifiers also effectively eliminate water pathogens. Imagine sitting on a beach in Mexico with a tequila-infused beverage with ice. Unsuspectingly, you get sick. Why? Ice is typically a huge source of sickness for travelers as it carries bacteria. UV light like the SteriPEN Ultra, a UV purifier can be put into the glass and swirled around to destroy pathogens that could cause an infection. We tested two UV purifiers in this review, the SteriPen and CrazyCap. Both are easy to use. The SteriPen is a long structure that you swish around in your water while the CrazyCap is a lid with a UV light built into the bottom, so purification happens inside the bottle. Both offer the same water quality level. Unfortunately, UV light purifiers won't remove particulates, smells, or metals and don't score as high as other purification models because of this.

Chemical Treatment

The Aquamira Water Treatment Drops is our favorite chemical treatment. It can kill most microorganisms but does impart an off-flavor to the water. In addition, they can't filter out particulates. The Aquamira drops are the best because they kill all organisms (with enough time) while the Potable Aqua Iodine Tablets and MSR Aquatabs can only destroy viruses, bacteria, and some protozoans, but not Cryptosporidium. The active ingredients in these treatments cannot get rid of Cryptosporidium as the drops do. The drops have the least "chemical" taste of all three options, which scored by points among our testers.

Water Filtration Units

A backpacking water filter (not purifiers) can remove particulates, bacteria, protozoans (Giardia & Cryptosporidium) but cannot remove viruses. The best filtration systems can remove chemicals, heavy metals, and odors using activated carbon embedded in the core of the media.

Of the backpacking water filters, the Katadyn Hiker Pro, Katadyn Hiker Microfilter, MSR Miniworks EX, and Lifestraw Universal offer protection from both microorganisms and chemicals like pesticides to improve the taste of the water. The LifeStraw Flex can remove lead, which is a unique property. This is an excellent option if you are concerned about lead in your water sources.

Filters that utilize a hollow fiber filtration media, like the Platypus GravityWorks and the MSR Autoflow XL, are plentiful in this review. If it doesn't have a carbon core, don't expect it to improve the taste of water or remove chemicals. These two gravity filters, for example, cannot remove these contaminants.

A Note on Water Turbidity

It's essential to plan for water sources that might be saturated entirely with silty sediment (called highly turbid). For example, the Colorado River that has carved out popular backpacking locations like the Grand Canyon is one of the most turbid rivers in the world. If you live close to it, you've seen it transform from a clear greenish color to what looks like chocolate milk shortly after rainfall.

Most backpacking water filters and purification systems cannot deal with the amount of sediment and silt in water sources like this. The only system that held up in these conditions is the MSR Guardian Purification System, another reason it's one of our favorites. It utilizes an auto backflush that cleans the filter with every pump.

If you plan on traveling to areas with high turbidity, bring a gallon ziplock bag or a bag designated for settling water. Scoop up the silty water and let it settle for a few minutes. Clearwater will remain in the upper column, with sediment falling to the bottom. Gradually pour the upper layers of water into your filtration device, or filter from the top of the bag. This is an easy and cheap "pre-filtration" technique for these areas. Some gravity systems have a "sediment collecter" in the bottom, like the MSR Autoflow XL.

Durability and Maintenance

Reliable backpacking water filters are durable in construction. You don't want to be without a filter simply because it gets dropped. You also don't want to spend hours maintaining it. 21st-century products are available that offer high quality and reliable with minimal durability.

The most durable and reliable products are chemical treatments. Each comes in either jars or prepacked packets that can go into a plastic bag. They have no moving parts, don't require maintenance, and don't expire. If you want 100% reliability, this is it. The Aquamira Treatment Drops is a favorite of ours. We would strongly recommend carrying these as a backup system, especially when traveling into the backcountry for extended periods of time. There are too many situations where filters can clog, parts might be lost, or things may not work. Carrying these treatment drops can mean the difference between life, death, and grave discomfort.

Gravity Filters

Of this group, the Katadyn system seems to be one of the best constructed. The bag, unlike the Platypus and both the MSR systems, seems to be far more resistant to punctures and has a lot less going on. The Platypus is made of a strong plastic composite that could come apart at the seams, while the MSR is made of a more rubberized plastic compound. Of all these systems, they all seem very durable and reliable, with the Katadyn being the best.

All of these systems have filters that require frequent maintenance and care, depending on how much sediment is in the water you are filtering. Both the Platypus and MSR systems use the same hollow fiber technology. It's important to know that regular back flushes are required, which is simply flipping the filter upside down and allowing water to run through it. Alternatively, the Katadyn requires a rinse and has more moving parts, which is hard to clean with water that isn't clear of sediment in the first place. All systems are pretty durable and easy to use; just be sure that you're amenable to their maintenance to retain optimal flow.

Of the three, the Katadyn is the only one that can be used after it's been frozen. Given the filter's internal glass fiber construction, the filaments aren't destroyed when frozen. While it can't filter water when frozen, it is still usable after thawing out. If you're seeking a gravity filter that'll do for a winter camping trip, this is it. That said, it's not freeze-proof. That'd be an amazing innovation.

Hand Pumps

These models are pretty durable in general until they get clogged. The MSR Guardian is the most durable and maintenance-free backpacking water purification system that we'd trust anywhere. It auto cleans, even in turbid water, offering the best reliability in terms of hand pumps. It can also be frozen, unlike any other hand pump system. The MSR MiniWorks EX is another reliable hand pump. It uses a ceramic-carbon core that can easily be serviced in the field. Unfortunately, it does require a lot of maintenance to keep it working well (lots of scrubbing), but it can be fixed in the field.

The Katadyn Hiker Pro and Katadyn Hiker models are two of the best selling models on the market. Both are extremely consistent in performance. Both use a glass fiber filter that, if you allow it to become completely clogged, needs to be replaced. Both can be serviced infield, but you must be careful not to keep pumping if performance decreases. Between the two, the Hiker Pro is better by a hair. It's more durable and performs a bit better. For the minimal improvement, though, we tend to recommend the Hiker. These pump filters require less maintenance than the MSR MiniWorks EX.

The MSR Hyperflow is the fastest flowing pump filter tested, but also requires the most service. The filter, when clogged, can only be backflushed. To do that, you need to take the system apart completely. It requires regular backflushing (every 8L in clear water, more in turbid), and is a bit of pain. It's a durable unit but requires quite a bit of care.

Squeeze Systems

We are super impressed with the Sawyer Squeeze, lasting up to 10,000 gallons and pretty well built-in nature. Sawyer offers three systems, the regular Squeeze, Mini, and Micro. With all these systems, the bags breaking when in "squeeze" mode are the most annoying. When squeezed too hard, the bags break at the seams, with the Mini being the most problematic of them all. The regular Sawyer offers a good amount of flow, with less squeeze-force required, breaking fewer bags overall. All of these systems do require you to carry a plastic syringe to backflush after most uses. Overall, the regular Squeeze requires the least maintenance simply because it's a bigger squeeze system than the rest.

Another great squeeze bottle is the Katadyn BeFree 0.6L, our favorite for lightweight missions like trail running. The bottle that it comes with is also prone to leaking. However, we found that it can be attached to other hand bottle options that are much more durable. Overall, its durability is a drawback, but the filter itself offers some of the best flow and adaptability. Cleaning is easy; just swish it in clean water. You don't need to carry any extra parts, and clogging does not happen often.

On-the-Go Systems

The Sawyer Squeeze and Lifestraw Personal Water Filter are two options that we really like. If you're seeking the most barebones option that doesn't require you to carry extra items, the Lifestraw is where it's at. It's light, easy to carry, and long enough to provide easy access to water sources. Both the Squeeze Mini and Micro are fine options for on-the-go carry but require you to carry a syringe and straw adaptor.

UV Light

This is one of the most unreliable systems simply because it needs a power source. Battery life can be tough to predict, especially in colder temperatures. The CrazyCap earns a higher score than the SteriPen here because it's completely waterproof. It also requires less time to charge overall. One charge lasted us about 30 liters but only took 1.5 hours to charge completely. After testing it for months, it was consistent. Neither are units we'd completely trust on a long backpacking trip, but both are suitable for travel or purifying municipal water sources on a regular basis.

Treatment Time

In this metric, we consider how quickly you can get water from the source to a filtered state. To test this, we noted if water filtration is instantaneous. If not, we performed three separate time trials and averaged them to determine an average time to filter one liter. The fastest times did best in this metric.

Straw Filters

The most immediate backpacking water filter systems are the straw filters that you can drink through immediately from a water source. The Aquamira Frontier Max and Lifestraw Flex are a few of our favorites. Water flow is typically slower but very much based on the construction of the input, filter body, and straw or bite value. For example, the Lifestraw Flex and Aquamira Frontier Max have comparable flow rates, not requiring as much effort as the laborious Lifestraw Personal Straw.

Squeeze Filters

These backpacking water filters use a collapsible bottle or pouch, offering a little water storage. The Sawyer products all demonstrate this adaptability, but our favorite is the Katadyn BeFree for its fast flow bite valve that delivers water quickly. This makes it a favorite among trail runners because water collection takes no time, and treatment is instantaneous.

Of all the Sawyer products, the Sawyer Squeeze offers the best flow rate. It can filter a liter of water in just 40 seconds when in squeeze mode. The Mini, the smallest of the group, takes 2 minutes to filter a liter of water, with the Micro somewhere in between. If you like the Squeeze products and want one with an awesome flow rate, the Sawyer Squeeze is the way to go.

Pump Filters

We pumped over 40L of water and timed it to see how many strokes each took, and which were the fastest. The hands-down winner in this category is the MSR Hyperflow (27 seconds, 29 strokes per liter). It pumps out hoards of water super quickly. However, this model was also the quickest to slow down, reducing its flow rate significantly as the liters added up. The MSR Guardian Purifier placed in second, filtering a liter in 37 seconds and maintaining performance in even the murkiest of water. The other pumps followed as such the Katadyn Hiker Microfilter (42 seconds, 52 strokes), then the Katadyn Hiker Pro (53 seconds per liter), and lastly, the MSR MiniWorks EX (80 seconds, 90 strokes per liter).

The Katadyn products and the MSR Guardian offered the most consistent performance overall, with these working best in Turbid conditions. The MSR Hyperflow and MiniWorks EX needed cleaning almost every 4L in these tests. In our sludge tests, all the pump filters needed to be cleaned out every liter, except the MSR Guardian.

Gravity Filters

Comparable in the flow rate, gravity filters are nice because you conveniently don't have to pump or do anything once they are set up. They can process large quantities of water, making them highly useful for small to large groups. All of the gravity filters are super close in treatment time.

The Platypus Gravity System is the fastest, filtering one liter in 52 seconds. The Katadyn Gravity Camp filters one liter in 64 seconds. The MSR Base Camp is close behind at 69 seconds. Lastly, the MSR AutoFlow XL took just around 2 minutes per liter, making it the slowest gravity filter tested. While gravity filters are inherently rad because there's so little work involved, there are some stark differences in performance. Please note that these flow rates will decrease with murkier or turbid water, and if the filters are not properly maintained. Also, note that if you aren't rushing, the difference in passively waiting one or two minutes for a liter of water to be filled often isn't a big deal.

Weight and Packability

Weight and packability are essential. If you're carrying less weight, long hikes can be more enjoyable. To assess this metric, we weigh each system and look at its relative profile. We tested them with hydration vests, backpacking backpacks, and regular packs. Generally, products that were lighter and easier to pack scored better than bulkier options.

Of all the treatments out there, chemical treatments are by far the lightest. If you're planning a long thru-hike or huge trail run, they're a great choice. Of the treatments, the MSR Aquatabs and Potable Aqua Drinking Water Germicidal Tablets can simply be put into a little baggy, without requiring you to carry the whole bottle. This helps to eliminate weight. The only downside is that both of these result in a chemical taste in the water (for most people). The Aquamira Treatment Drops can't be parsed out like the tablets, but some prefer them because they don't taste as bad as the tablet options.

The lightest filtration systems out there are on-the-go systems like the collapsable Katadyn BeFree and Lifestraw Personal Filter. The lightest purifying on-the-go filter system is the Aquamira Frontier Max. Of the gravity filters, the Platypus Gravityworks is the lightest and most packable (11.5 oz). If you prefer a hand pump system, the lightest systems are the MSR Hyperflow (10.6 oz) and the Katadyn Hiker Pro (13.2 oz).

Ease of Setup

We measured ease of setup based on how intuitive backpacking water filters are and how many steps each one requires to set up. We also consider how easy it is to access different water sources.

The easiest setups are the ones that require little thought and easy access. The best score models have no parts to carry around or steps to follow. On-the-go systems prove to be the easiest here. The basic Lifestraw is the best for this. Unlike other more complex on-the-go systems, this filter requires you to find a puddle or accessible water source and simply drink.

Purification Tablets are also pretty simple. Those like the MSR Aquatabs and Potable Aqua Drinking Water Germicidal Tablets require you to drop them in the water and wait. The Aquamira Water Treatment Drops are also pretty simple, but with a steeper learning curve. These require you to follow a series of specific steps where you have to mix two solutions and wait a specified time amount of time. The time frame depends on what contaminates you need to eliminate from the water.

Hand pumps are also relatively easy to set up and offer great access to all sorts of water sources. The Katadyn Hiker Pro, Katadyn Hiker Microfilter, and MSR MiniWorks EX are favorites because the intake can grab water from the smallest nooks and crannies. The MSR Guardian works well for this, but it has a larger particle screen that makes it harder to reach shallow sources. Pump filters excel at reaching water over steep banks, boat sides, or fast rivers when water access can be an issue.

Gravity filters require more effort to set up because you need a place to elevate them. The ideal scenario is to hang the filter from a branch. If that is not available, you may need to get creative in a pinch; a rock could work. They typically earn a lower score in this category. Reservoirs that are very flexible with large openings like those found in the Katadyn Gravity Filter can get water from most water sources. However, because you have to scoop up water, the source needs to have a sufficient pool to collect water. Shallow pools are harder to reach.

Ease of Filtration

In the ease of filtration metric, we look at the amount of effort required physically to get water through the backpacking water filtration system. While we don't score storage capacity, we note how much water each system is designed to store or not store.

UV Purifiers

Of all the categories, both the SteriPen Ultra and CrazyCap require the least amount of work. Simply fill up the bottle and turn the light on. The SteriPen requires a little less time to filter a liter in comparison to the CrazyCap. However, we appreciate that the CrazyCap is completely hands-free, and you can keep hiking while it purifies your water.

Gravity Filters

Gravity backpacking water filters are by far the best systems when it comes to ease of filtration. After set up, the filtration process is hands-free. All gravity filters in our review earn top points, all being easy to filter. These filtration systems can move lots of water quickly, making them a top choice for groups. One difference is the height requirement to filter. The Katadyn Gravity works needs full suspension and can't be put on the ground, while the MSR BaseCamp, MSR Autoflow, and Platypus Gravityworks can be laid on a hill or over a rock and still filter water.

Some come with "clean water" vessels like the MSR Basecamp and Platypus Gravityworks while others like the Katadyn and MSR Autoflow have a simple hose running from the bag to a storage vessel of your choice. All prove to adapt nicely with a hydration bladder and can be filtered into a bottle if needed.

Hand Pumps

Hand pumps are a little harder to use as you need to pump to move water through the system physically. Hand filters vary by design and efficiency, which is dictated by output per pump. Of the hand pumps we tested, the MSR Hyperflow and MSR Guardian are the easiest to use. Both are highly efficient filters, which translates to less pumping and more water production. The Guardian has a large handle that's easy to grab, similar to the MSR MiniWorks EX. The MSR Hyperflow has a tinier system, but it's still pretty ergonomic. All hand pumps we tested have attachments that fit a Nalgene bottle best. The Katadyn Hiker models both have easy to use handles, but they aren't as ergonomic as the MSR products. These also require more pumping to get more water. The MSR MiniWorks EX took the most work per liter of all the hand pump filters.

On-the-go Filters

On-the-go backpacking water filtration systems are typically easy to set up but are propelled by either sucking or squeezing forces. Of the on-the-go systems, the Katadyn BeFree, Sawyer Squeeze, and Aquamira Frontier Max are the easiest to suck through when in straw style. Others are harder, like the Sawyer Mini, which gives you very little water for each suckle. We also love the Lifestraw Adaptor Kit that turns a personal water bottle into a filtration system.

These systems don't offer much when it comes to water storage; however, they are adaptable. For example, Sawyer products come with a storage pouch that you can use to store water. Though, if you don't trust these bags, you can find a hydration bladder, a suitably-sized collapsible bottle, or even a regular water bottle that is compatible to use instead. You can also simply carry a "dirty Nalgene bottle" and drink through the on-the-go filters. Be aware not to drink from this vessel without the filter.

The Katadyn BeFree bottles have a few different sizes and are compatible with other soft bottles that offer better durability and flow. But for the most part, they are designed to be carried where water sources are plentiful. You can also fill up a "dirty bladder" and carry it around with you, filtering in rounds and drinking on the go.

Conclusion

Selecting a backcountry water filter for a remote backpacking trip is one of the critical gear decisions you'll have to make to help ensure a successful and well-hydrated trip. After years of experience testing and comparing each option, we hope that our recommendations have left you feeling good about buying a reliable product that will filter or purify water for your planned adventures.