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Little else ruins a good backpacking trip like a midnight run for the bushes. We’ve been there, and we’re not keen on going back, which is why our experts have found the best backpacking water filters. We’ve spoken to thru-hikers, hunters, and mountaineers, and we’ve logged a not small number of miles ourselves, filtering our water along the way.
Our experts collectively tested a wide range of filters for the creation of this guide, from our top-pick Sawyer Squeeze to the budget-conscious LifeStraw Personal. We’ve been squeezing water through countless tubes and dropping tablets in Nalgenes each season to bring you the streamlined selection of 15 filters you see today.
From stagnant green pools in the African savanna to bubbling alpine brooks in the Cascade Mountains, we’ve filtered water of all consistency and color in the wild and bring only the best filters on our excursions. Rest assured, we would trust every model in this guide to keep us safe and hydrated in the backcountry.
Editor’s Note: We updated our Backpacking Water Filters guide on January 30, 2025, to add information on different filter membranes to our Buyer’s Guide and additional specifications for each filter to help differentiate them.
This Sawyer Squeeze ($41) is the gold standard for many thru-hikers and backpackers across the globe. The membrane filters down to 0.1 microns, making it effective against bacteria and protozoa (thus, slightly more effective and safer than other filters). Newly updated with a better flip cap, this filter can be used with a water bladder, directly from a bottle, or inline in a hydration system.
Given our bench-testing, the given flow rate of 1.7 L per minute seems accurate to us, though this number can be harder to recreate halfway through a thru-hike. Senior Editor Nick Belcaster used the Squeeze as his primary filter for his Pacific Crest Trail thru, and it performed admirably. From high desert cisterns of unknown quality to sources in the Sierra that likely didn’t even need it, the Squeeze was dependable.
During this time, he sparingly backflushed the filter and, when needed, found a sports cap and Smartwater bottle combo to recreate the pressure provided by the syringe that comes with the Squeeze. For longer or more remote expeditions, the syringe is a nice addition to bring along.
We’ve also played around with the hydration pack inline set-up with the Squeeze, and while functional, we found it a bit finicky. Best to leave this filter mated up to a water bladder, or, straight from a soft drink-threaded bottle.
The pouches that come with the Squeeze aren’t the best and form pinholes where they’re folded repeatedly. During his thru-hike, it was only a couple hundred miles before Belcaster’s pouches bit the dust (and, based on the number of similar bags found in hiker boxes, he wasn’t alone). A popular upgrade is to snag a CNOC 2L Vecto bladder, which is far easier to scoop water with and much more durable.
We love that there are no annoying tubes — you just screw the filter onto the squeeze bag or a bottle and drink. For overall ease of use and durability, the Squeeze has earned its place at the top of the list.
The LifeStraw Personal ($20) is one of the most consistently high-rated water filters of all time. The simple straw-style filter uses a hollow fiber membrane that filters out bacteria, protozoa, and microplastics down to 0.2 microns (the standard for water filters). It’s also the lightest on the market at 2 ounces and costs less than lunch these days.
That said, it’s only good for drinking water directly from the source and doesn’t work for filtering into bottles, so it has its limitations. For long-distance backpacking, you’ll probably need a secondary water filtration method. But it’s a great budget pick and a solid option for emergency kits, backpacking, hiking, bugout bags, or international travel.
In full honestly, however, the best use we were able to drum up for the LifeStraw is to bring along while flyfishing or kayaking. Being in the water all day makes the most sense for a filter like this, and we loved leaving our bottles behind and sipping straight from the source instead.
There’s a set of flip caps on both the inlet and output sides, which means that you can deploy this filter quickly and when you’re done, not worry about grunge making its way in there. There’s little to no restriction on the flow rate when drawing through the filter, so don’t feel like this is a milkshake through a straw scenario. We could take full gulps through the Lifestraw.
For the ultra-minimalist, or the backpacker who wants an easy-to-use option they can pull straight from an outer pocket of their pack, the LifeStraw Personal is a must-have. If the filter-as-you-go style is what you’re after, but you want a means of moving some water as well, check out a filter bottle like the LifeStraw Go Series or Grayl GeoPress.
Read Review: First Look: Katadyn BeFree Water Filter
To justify taking anything on an extended thru-hike, it needs to be dependable, lightweight, and durable enough to last for months of torture. Today, you usually see one of two popular filters being used by long-distance hikers on trails like the PCT and AT: the Sawyer Squeeze or the Katadyn BeFree ($40).
One of the authors of this guide has taken the BeFree on three different thru-hikes across America and has nothing but praise for this tiny ultralight wonder. At 2.3 ounces, it barely registers in your pack. The filter membrane has a lifespan of 1,000 L and a flow rate of 2 L per minute, bumping it just ahead of the Squeeze and many others in the flow department.
Its 0.1-micron microfilter allows you to confidently gulp down any water you encounter on a long trail (though the murky cow troughs in New Mexico on the CDT did have our tester filtering twice), and the high flow rate means you’re not wasting a bunch of energy just to get a sip in. The wide mouth of the flexible flask allows it to fill up in just a couple of scoops, and you can clean the filter by simply swishing water around in the flask.
It’s not flawless, though. First, it isn’t as versatile as the Squeeze in that it won’t fit over standard water bottle mouths (this isn’t an issue if you plan to just use the included flask or other 42mm bladders such as HydraPak).
Second, it tends to clog a little faster in filthy water than other filters, including the Squeeze. The cleaning method also isn’t as flawless, as it has you shake the debris free instead of forcing it out with water.
Those gripes aside, this is still the top pick for hundreds of long-distance hikers, and for good reason. If you’re looking for an ultralight filter with a solid flow rate for long adventures, don’t pass the BeFree 0.6L by.
If you really don’t want to sacrifice weight for a filter — or are in an area that eats filters for breakfast — chemical treatment is a great option. Katadyn’s Micropur M1 Tablets ($16) have been a top choice over the years, thanks to their purifying powers and easy-to-use instructions.
Our exploits have taken us to high-alpine outflows where every water source is heavily laden with glacial silt, and for quick filtration, chemical tablets do the trick (though we sometimes prefilter a bit with a bandana). Otherwise, these tabs ride along with us in our emergency kits, as they’re about the lightest option you’ll encounter, and less likely to spill than chemical drops like Aquamira.
Some claim there is a slight aftertaste, although we like these much better than other chemical treatments. Also, we agreed that learning the wait times is important. The tablets destroy viruses and bacteria in 15 minutes, but it takes 4 hours to kill the pesky cryptosporidium parasite. This is a good bit longer than our second choice in chemical treatment, Aquatabs (30 minutes to clean), but if you’re using chemical filtration, you’ve likely got some time to kill anyway and may as well kill everything.
For backpacking trips, you can use tablets in the evening to ensure that you have clean water for the next day. These are also great options for trips where you’re operating out of a backcountry base camp for side excursions. Most filters have the potential to fail, so having a few Micropur Tablets stashed away for emergencies is smart.
Read Review: Fast & Clean: Katadyn BeFree 3L Gravity Filter First Look
Gravity filters use the force of gravity to pull water through the filter. For that reason, they’re extremely user-friendly. Just fill it with dirty water, hang it, and come back in a few minutes to find filtered water waiting in another container. They work great for larger groups or when you want to filter a lot of water all at once. They’re also quite light, given their speed and ease of use.
At just 6.8 ounces, the Katadyn BeFree Gravity Filter ($75) is the lightest gravity filter on this list, beating out the Platypus GravityWorks by 5 ounces. Using the same filter element as the handheld BeFree, this setup filters 3 liters at a time and comes with a quick-connect output hose to easily fill multiple bottles, pots, or bladders. The wide-mouth port on the dirty-water bladder makes filling up quick, and a simple shutoff valve makes filling different vessels easy.
It also doesn’t require commonly involved filter maintenance like backflushing — since it clears itself with a vigorous shake of the filter. Similar to the Sawyer Squeeze, the flow rate is great, and because the bag rolls down, it’s fairly packable.
The expected filter lifespan of 1,000 L is likely on the conservative end, but it is a good bit lower than the 100,000 gallons (that’s 378,541 L) that the Squeeze claims. Our testing has shown that the BeFree will last for at least an entire thru-hike, at least.
Overall, it came in behind the Sawyer Squeeze in our testing, largely because it’s more expensive. However, for those who don’t mind spending a little more or are traveling as a bigger group in the backcountry, this is one of the best backpacking water filters available. It’s proven itself over many backpacking and hunting trips in the Rocky Mountains and beyond.
MSR makes a few pump filters, but this one is our favorite. The MSR MiniWorks EX ($120) protects against bacteria, protozoa, heavy chemicals, and particulates. One of our favorite features of this filter is the fact that it’s compatible with both MSR Dromedary Bags and Nalgene bottles, so you can easily attach and pump into your drinking vessel.
Pump filters aren’t as prevalent today as they once were, but that doesn’t mean they don’t have a place. Large groups are an excellent place to deploy a pump filter like the MiniWorks, where ease of use and not having to refill a dirty water bladder constantly can save time. It’s also pretty foolproof to stick into someone’s hands and educate them quickly: Stick this end in the water, then pump.
The filter element is ceramic, meaning you clean it over time instead of replacing it (although you may need to replace the tubing). This field reparability is a pretty common theme among MSR kit — such as the brand’s expedition stoves — and it’s something those on long river trips will come to appreciate. The filter’s carbon core also does some heavier lifting than comparable filters, sucking up heavy metals and organic compounds.
During testing, we had a few users note an issue with pressure building up in the filter chamber, causing the flow rate to slow. We still found we could hit the rated 1 liter per minute, but only with some good arm muscle. MSR says that a tempo of around 70 to 80 pumps a minute is prime, and we’d agree. The $120 price is a bit on the high end for pump filters, but if you’re after the best, this is it.
The MiniWorks EX is the filter we’d reach for on a float down the Grand Canyon with friends, and that’s where it’ll excel. Pro tip: using a ‘flocculant’ such as Water Wizard For River Runners before filtering super sedimented water will condense large particles together, making for easier filtering.
Read Review: GRAYL Geopress Purifier Gets an Ultralight Upgrade: Geopress vs. Ultrapress Review
The Grayl GeoPress ($100) uses electroabsorption and activated carbon to purify water. Simply fill, press down, and drink. It is that fast. (And yes, the convenience, fast filter time, and quality of this filter make it worth the price.) Of the bottle filters available today, this is our favorite.
This is truly the best if you’re drinking from really sketchy, off-grid water sources or want a filter for backpacking that isn’t a bladder and hose system. The activated carbon filter medium goes a step beyond most other filters in protecting against heavy metals, chemicals, and viruses — in addition to common protozoa and bacteria.
We’ve tested this filter abroad and love it for international travel. It’s ideal for when you want to filter all tap water before drinking, and it works wonderfully as a constant companion to keep you hydrated on the go. We’ve also used it backpacking and thru-hiking on the Appalachian Trail. For one or two people, the GeoPress is an awesome purification method.
One of our biggest issues with other filter bottles, such as the LifeStraw Go, is the inability to add powdered drink mixes to our water on the go. Thanks to a recent design update, Grayl incorporated a one-way Drink Mix Valve into its filters, meaning you can load up the electrolytes without worrying about clogging your filter. Very slick.
We love the GeoPress’s fast flow rate of 5 L per minute (under 30 seconds to get clean water). The top complaint is its size (though it’s not any bulkier than a Nalgene). Also, the replacement cartridges are expensive at $30 and need to be replaced every 250 L. All that being said, however, this is an easy go-to for international travel, or shorter day trips where you won’t need to camel up on water.
Clean water in the backcountry is essential, and the seven filters we’ve awarded above are just about the best of the lot. That doesn’t mean they’re the only options out there, and we’ve used plenty of other worthy filters on our travels. Check out the lineup below before making your choice.
Sleek, lightweight, and thoughtfully designed, the newly minted LifeStraw Go Series ($45) filter bottle is ready for a rowdy road trip across Mexico or a casual day on the river. Its streamlined, stylish design joins forces with a 0.2-micron filter and 4,000L lifespan to deliver a hard-working portable filter that’s equally at home on trail or around town.
Muted and flashy colorways abound for whatever your vibe might be, and the quick-release top handle protects the nozzle, allowing it to be carried around with ease. It’s crafted with surprisingly quality materials for such an affordable model, and has a premium, top-shelf feel. While we love the ability to swiftly unscrew the top handle and snag a quick slurp, we found it can sometimes pop off when we don’t want it to, as it’s only screwed on by a couple of threads.
At $45, this is one of your best bets for a budget filter bottle. It uses the same type of hollow-fiber filter as the original LifeStraw but seamlessly incorporates it into a BPA-free plastic bottle, that’s now made from 50% recycled plastic. The filter straw takes a bit of a suck initially, but soon flows with ease, and has a phenomenally natural taste to it. We do wish it extended a bit lower into the bottle, as we regularly have to pour out a few milliliters of unfiltered liquid — which is a bit deflating on a backpacking trip.
The 22-ounce bottle is a solid alternative option to the straw if you won’t be near water sources as frequently. The activated carbon filter reduces chlorine, organic chemical matter, and odors for a better taste than other filters we tried, making it a fine bottle to tote around on daily outings.
Similar to the original LifeStraw, we love that the Go Bottle is quick and simple to use. It’s even easier than just the straw, as the bottle provides a way to carry and store water when you aren’t near a source. We also dig the approachable price point.
Read Review: MSR Guardian Purifier — Last One You’ll Ever Need
The MSR Guardian Purifier ($390) filters out nearly everything (including viruses), has an excellent flow rate, and even self-backflushes during use. For most people and places, however, it’s downright overkill. If you’re setting up for a serious adventure that requires filtering a lot of very sketchy water, however, you may want to consider forking over the cash.
The difference between this filter and the more affordable MiniWorks EX is both a higher flow rate (more than twice the capacity) and the pump’s self-backflushing ability. The pump accomplishes this by using 10% of the water it filters to clear the membrane and flush back into the source with the second tube. The unique uptake float keeps the supplies separate and means your time to clean this filter is near zero.
The Guardian physically removes viruses, bacteria, protozoa, and particulates, including hepatitis A, E. coli, giardia, cryptosporidium, and more. Just be ready to lug a large item that weighs in at over a pound.
The MSR Guardian is probably one of the best backpacking water filters on the market. So why didn’t it top the list? Well, in two words, price and weight. It costs a pretty penny at $390 and weighs considerably more than other filters. We find that most users will be better suited by the MiniWorks EX filter, which still accomplishes the same feats, just a bit slower and with some additional cleaning.
Read Review: Water Filter Review: Small & Speedy Platypus QuickDraw Rivals Sawyer Squeeze
A newer filter system on the market is the small and packable Platypus QuickDraw. We tested it for several months last year (and plan to use it a lot more this year) and love its low weight, packable size, and good filter rate.
The QuickDraw’s hollow fiber filter component and 1L plastic reservoir come in at just 3.3 ounces. The dual-thread design is awesome and allows you to screw the filter onto both the reservoir and a threaded plastic bottle (like the popular Smartwater bottles).
We found it super easy to use and backflush, and we experienced a good flow rate. The filter is good for 1,000 L before it needs a replacement.
Factoring in the size, weight, and price, this filter nearly made it higher on the list. But the Sawyer Squeeze filters down to 0.1 microns — slightly better than the QuickDraw’s 0.2 microns — for a few bucks less. Overall, the Quickdraw is still one of the best backpacking water filters you can buy.
The Katadyn Hiker Microfilter ($90) has been one of our long-time favorite pump filters for its great price and performance in the long run. Several users found it can last for 2 to 6 years before having to replace the filter, and for a pump filter, it’s on the more affordable side.
The Hiker filters bacteria, protozoa, microplastics, and chemicals down to 0.2 microns, which is comparable to other pumps like the MSR MiniWorks EX or Guardian. Like the Guardian, the Hiker Microfilter also implements a prefilter on the intake side to cut down on the amount of large debris that reaches the main filter element — greatly increasing the time in between cleaning.
Filtering is quick enough at 1 L per minute (which we had no problem hitting in our timed tests), and despite the more old-school design, pumping wasn’t a chore to get through water for a crew of hikers. The included bottle adapter is quick to fill up Nalgenes, and while we haven’t tried out the hydration reservoir adapter yet, it seems to be a quality design for those who use bladders.
So why doesn’t the Hiker Microfilter place higher in our lineup? It’s our opinion that the MSR MiniWorks EX and Guardian simply do the job better, and are easier to field clean (often an issue when filtering the sediment-thick waters you’ll purify with a pump filter). The ABS plastic exterior of this filter is also pretty slick, and because of the downward direction you’ll need to pump in, it can be a little tricky to get a good grip on when pumping for a while.
For $90, however, it slides in below both of those filters, and if you’re after a pump filter but don’t want to spend more than $100 to get one, the Hiker Microfilter can be a smart buy.
Read Review: I Hiked the Entire Appalachian Trail Testing This Water Filter: LifeStraw Peak Gravity 3L and Peak Squeeze Water Filter Review
We put the new LifeStraw Peak Series — a personal straw filter, squeeze filter, and gravity filter — to the test this spring on the Appalachian Trail. The Peak Series Personal Straw Filter ($25) and Squeeze Filter ($44) turned out to work great for filtering water at various sources in the backcountry.
The personal Peak Series filter worked extremely well and had a good flow rate. After 20+ years of LifeStraw being on the market, it was nice to finally see a big upgrade in materials and design.
The new design is comfortable, easy to use, durable, and easy to clean and backflush. If you’ve used a LifeStraw filter before and are maybe looking to replace it, we definitely recommend the Peak Series version.
The LifeStraw Squeeze Filter also performed well in testing, though not as much as others on our list. It’s modular, so while it has the filter incorporated inside the squeeze pouch, you can also move it to the outside (and swap out the cap) if filling bottles or not drinking directly from the filter. Both are a great price.
The Platypus GravityWorks 4L ($135) has won a spot on our list for another year in a row. Why? The Platypus is good for when you need water for more than just drinking (straw filters are great, but not for filtering several liters of water at a time).
So far as gravity filter systems go, GravityWorks is the full ticket, with other systems like the Katadyn BeFree Gravity Filter only providing a single dirty water bag. The Platypus option instead hooks it up with both dirty and clean 4-liter bladders, and tacks on a few other niceties that might lure you to this setup.
The quick disconnect hose on the dirty bladder side was one of those perks, which meant that we could fill up without the need to bring the entire filter system with us down to the water source. The wide-mouth opening of this bladder is also nicer to use compared to the screw-top mouth of the BeFree Gravity, though we did find that it doesn’t always stay closed.
Filter rates are about on par between these two options, with the slight edge going to the BeFree. We did find that sometimes the GravityWorks could develop an airlock when first being set up — something that’s easy to remedy by elevating the clean side bladder for a minute to bleed out the air. Then, it’s smooth sailing.
Both gravity systems work great, and between the two, it’s tough to call either a clear winner. Those familiar with the BeFree system will find it an easy choice, but if you’re already plugged into the Platypus world with their hydration bladders, the GravityWorks 4L could be a great way to go for large group filtration.
Read Review: MSR Guardian Gravity Purifier Offers Epic Viral Protection, 10 Liters at a Time
With an easy-to-fill 10L reservoir and a 1L per 2-minute flow rate (which the brand claims is 2.5 times faster than the competition), the MSR Guardian Gravity Purifier ($300) takes technology designed for the military and brings it to groups of backcountry explorers.
The purifier meets NSF P248 testing standards, removing bacteria, protozoa, pathogens, and viruses through the 0.02-micron hollow fiber media. With an activated carbon component, it also pulls out chemicals, tastes, and odors — something that other gravity systems like the Platypus GravityWorks or Katadyn BeFree Gravity don’t host.
MSR’s setup is simple, even if you do need ample space to get the dirty reservoir at least 6 feet above the clean water receptacle (fairly common for gravity water filters). The speedy flow rate is ideal, and the bottle adapter fits a range of sizes to allow the filling of separate water bottles or a larger container with the entire 10 liters.
This new purifier is up there as one of the best backpacking water filters for larger groups. With no backflushing required and a mesh carrying case, teardown is quick and easy.
If you’re going where there are no trees for hanging, this could be tricky. Also, at over a pound, it really only works for larger groups where you can split up the load. In our opinion, one of the only reasons we’d opt to use the Guardian Gravity over other gravity systems is if you know you’ll be heading into an area where water taste is a known issue.
UV filters are popular for a lot of reasons. They don’t require pumping or filtering, and the wait time to kill bacteria and viruses is fairly short (between 60 and 90 seconds).
Our first SteriPEN Adventurer ($120) recommendation came service of a mountain guide who had done the tango with suspect water one too many times and burnt out his gut flora — making the common chemical treatments alpinists use no longer an option. He praised the UV filter as being simple to use, long-lasting enough to get him through week-long mountaineering courses, and hard to break — an essential.
Using the Adventurer is pretty simple: just get your bottle of water ready (wide-mouth bottles are essential here), activate the UV light, and stir for a minute and a half. There are two options: 1 and 0.5 liters, but either way, once your time is up, everything nasty is sufficiently zapped.
This type of filtration won’t take out particulates in your water, so take some advice from our mountain guide friend: filter through a bandana first.
At 3.6 ounces, the SteriPEN is a little bit heavier than other filter options like the Sawyer Squeeze or Platypus QuickDraw, but if your water is fairly clean to begin with, the speed at which you’re able to go from dirty to drinkable can’t be beaten by those filters. Longevity isn’t a problem, either, with 8,000 treatments being standard.
The rather inexplicable part about the Adventurer is that it runs on CR123 batteries and not a rechargeable internal battery. Most backpackers today carry some type of external battery pack, and recharging the SteriPEN would be simple to do. Bumping up to the SteriPEN Ultra ($130) will get you that USB charging ability, but in a bigger footprint.
Even still, for shorter trips where quick filtering is key (or you’ve been unkind to your gut biome), the SteriPEN Adventurer can be a key pickup toward getting your water quickly.
The GearJunkie team is made up of adventurers from a plethora of different outdoor sports and activities, but each of their hobbies requires a central discipline: proper water filtration in the backcountry. It’s key to survival, and if done poorly, can quickly put you in a dangerous situation.
For this guide, we carefully scrutinized the most reliable, functional water filters that outdoor enthusiasts from all ends of the spectrum depend on in the wild. We brought each of these filters on adventures and made sure that we would feel comfortable with all of them as our primary means of accruing filtered water in the field.
Our water filter field testing begins the second we jump out of our rigs and onto the trail, heading straight for the first water source. We often test filters side-by-side to gauge filter rates, ease of use, and frequency of needed cleaning. We make sure to test both clear as well as more suspect sources, as well as use these filters solo and in large groups to best identify user needs.
To date, we’ve sent filters out on entire thru-hikes of the Appalachian, Pacific Crest, and Continental Divide Trails. These feats of endurance are true tests of a filter’s mettle, and we’ve seen a not-small number of them bite the dust and hit the hiker box. While some filter lifespans are exceedingly long, we’ve certainly hit the ceiling on a few.
Outside of the field, we also put these filters through a more standardized set of tests in order to get some hard numbers on performance. Most filters these days work spectacularly, so in many cases, our decision to recommend one over another comes down to a few more pumps of a filter.
Independently verifying weights and packed sizes is a quick and easy way to ensure we don’t upset the weight weenies on staff, and we weigh systems all together to ensure we’ve got the full picture. Flow rates, too, are a simple test to compare side-by-side with manufacturer claims, and are important to independently verify outside of the field.
Finally, as a true test of grit, we whip up a rather dingy soup from our compost bin as a final test for these filters. It’s a tough test meant to bring these systems near to clogging, but it separates the just-OK filters from the winners. It also sets us up perfectly to execute our cleaning tests, where we sample the ease of restoring a filter to close-to-new functionality.
Guide author Mary Murphy curated our initial selection of 14 filters back in May 2020. A prolific backpacker, Mary knows the value of a reliable filter for constant, dependable hydration in the backcountry. Tester Chris Carter took over this guide in August 2022 and has been digging through his gear closet and scouring the internet ever since to bring you the most current, deserving selection possible.
Chris has thru-hiked the Triple Crown of long trails (the Appalachian Trail, Pacific Crest Trail, and Continental Divide Trail) and continues to pursue long-distance hiking around the world. Significant time backpacking and hitchhiking around East Africa forced him to purify water of the grimiest sorts and made him religiously fastidious in his hydration practices. He’s suffered from his fair share of water-born pathogens and will only rely on the best of the best to filter his fluids on any adventure.
GearJunkie’s Camp, Hike, and Backpack Editor, Will Brendza, also contributed to this guide. Will has been professionally testing and reviewing outdoor gear for over 15 years and spends an inordinate amount of time out on the trail. He’s constantly testing and reviewing the latest and greatest outdoor products, including water filters and purifiers, to find the best gear to make his outdoor adventures more enjoyable.
Water filters and purifiers work in similar ways, but it’s helpful to know the difference when choosing. Filters protect against protozoa or parasites (such as cryptosporidium and giardia) as well as bacteria (like E. coli or salmonella), microplastics, dirt, and debris.
Bacteria is the main concern when you’re drinking out of unsafe water sources in the backcountry or remote areas. Popular filters include the Sawyer Squeeze and the Katadyn BeFree Gravity filter.
Purifiers go an extra step by protecting against and filtering out viruses. This is more of a concern when you’re traveling internationally or to rural places where clean water may not be accessible. Products like the MSR Guardian and Grayl GeoPress Bottle will purify your water while also filtering out larger debris, while purifiers like the SteriPEN Adventurer use UV light to purify water, but won’t clear the water of visible dirt and sediment. You can run the water through a bandana or t-shirt first before using these types of purifiers to clean out the biggest particles.
For truly heinous dirty/stagnant water, it can be wise to use a number of different methods to make certain you don’t get sick. Some will filter their water with something like the Platypus QuickDraw, and then boil it, add a purification tablet like Katadyn’s Micropur M1 tablets, or add a couple of drops of bleach to ensure everything is killed. This can be time-consuming and make the water taste interesting, but it’s far better than catching a trip-ending sickness in the wilderness.
There are a variety of different types of backpacking water filters, and we cover a broad range of them in this guide. Each one has its place in the backcountry, and which type you choose will depend on how clear the water will be on your adventure, how lightweight you are trying to go, and if you are traveling internationally.
These filters use gravity to pull water from a dirty bag, through a filter, and into a clean bag or directly into your mouth. These are often the easiest filters to use as you simply hook it up to a tree branch or tent and wait. These are usually heavier and take some time to set up, so aren’t the best options for fast and light missions. They tend to work best for large groups or to keep around a base camp.
Gravity filters allow you to keep a large amount of water handy, but they can be difficult to fill up in shallow water sources, so keep that in mind when choosing a campsite. We found the Katadyn BeFree Gravity filter to be one of the best options for large group trips.
Inline filters are often used in gravity systems, but they can also be paired with a hydration pouch or water bottle for quick use. Filters such as the ubiquitous Sawyer Squeeze or the Platypus QuickDraw can be used in this way.
These generally rely on the user sucking the water from a pouch or water bottle, through the filter, directly into their mouth. With the correct adapters, several models of inline filters can be used with a hydration pack you may already be carrying, offering easy filtration without adding much weight.
While we don’t recommend them as your primary method of water filtration in the wild, straw filters are undeniably one of the easiest ways of procuring fresh water fast. Our favorite budget filter, the LifeStraw Personal, fits this bill. These filters are great for trail running, mountain biking, or as a backup to your primary filter. They allow you to get down and dirty by a stream or lake and drink directly from the source by sipping the water through the filter like a straw.
The main downside to straw filters is that they don’t offer any way to carry filtered water with you, unless you can fit the straw into a water bottle of dirty water you are carrying with you, which can be really annoying. It can also get frustrating having to practically lie down on muddy or rocky banks to get a drink any time you get thirsty. These filters suffice for day hikes, but you’ll probably want something different for any extended backpacking trip.
Pump filters, such as the MSR MiniWorks EX, work great for pulling water out of shallow pools or creeks and can be a solid choice for small backpacking groups. They tend to run on the heavy side, take a little more effort to use, and can be quite complicated to clean. For these reasons, you don’t see as many pump filters in the backcountry as you used to, but they do still have their place.
In some cases, as with the MSR Guardian, pump filters do a better job of purifying truly nasty water by removing viruses, bacteria, and protozoa, such as E. coli, giardia, and cryptosporidium. This is something to consider a little more seriously while adventuring internationally.
Water filter bottles are handy for traveling, road-tripping, or light hiking, but they are often heavy for dedicated lightweight backpacking trips. Some of these bottles, like the LifeStraw Go Filter Bottle, filter water with a simple hollow-fiber straw that extends from the nozzle into the water, while others use fancier technology to deliver a pure, fresh swig.
The Grayl GeoPress uses electroabsorption and activated carbon to purify water by simply pressing it firmly on the ground. This isn’t your average Nalgene! If you want to nerd out a little more, check out our in-depth review of the GeoPress .
Finally, purifying your water chemically or with UV light is another simple way to target viruses that may be present in a water source, as opposed to just bacteria and protozoa. Chemical purifiers use iodine or chlorine dioxide to deal with contaminated water, while UV purifiers employ ultraviolet rays.
Some backpackers will also use bleach to treat their water (two drops per liter, then wait 30 minutes). This is a super simple solution but does leave your water tasting, well, somewhat like a pool.
We like Katadyn’s Micropur M1 tablets for chemical treatment, as they tend to leave a more subtle aftertaste compared to other brands. The SteriPEN Adventurer has been our go-to UV filter for its long lifespan and light weight.
This is a great way to purify your water more effectively, but since these don’t have filters with them, it’s important to use them with clear water that doesn’t have a lot of debris in it. Chemical or UV purifiers are lightweight and simple, but should probably not be used as your primary method of filtration on a backpacking trip.
It’s hard to get filtered water fast — they can leave an unsavory aftertaste and sometimes rely on batteries and electronics (in the case of UV purifiers). Since they are so light, however, it’s always a good idea to have them as a backup.
Any filter that uses a membrane to separate the nasty bits from your water (note: not chemical or UV filters) will do so through pores in the membrane material. These pores are measured by their micron size, and they’re a good indicator of not only how effective your filter is but also how fast it will filter water.
For example, the Sawyer Squeeze filters down to 0.1 microns, which is just about the standard you’ll see. This is fine enough to catch particulates, bacteria, and protozoa but not small enough to nab viruses.
Alternatively, the Platypus QuickDraw uses a 0.2-micron membrane, which filters the same way but at a higher flow rate. On the trail, this means you can filter more water faster.
If you’re adventuring somewhere with especially sedimented water, such as rafting the Grand Canyon, an extra step is usually necessary to keep your filter elements from clogging prematurely. That is unless you’re using the MSR Guardian, which backflushes the filter with every pump. For every other type of filtration system, use a flocculant such as alum powder (easy to snag in any grocery store), which will accumulate and settle the sediment for you.
Our picks for best water filters vary widely in terms of how quickly they can filter water, ranging from 30 seconds to 30 minutes to 4 hours (chemical treatments). Types of filters and methods of purifying will play a part, as will flow rate.
Flow rate is a unit that measures how quickly a certain amount of water can be filtered. Flow rates for gravity, pump, or squeeze filters listed here vary anywhere from 1L to 3L per minute. If you are encountering a slow flow rate with your filter, it may require priming or backflushing.
Similar to needing to prime a stove, some water filters require priming before initial use. Check the instructions (it varies by filter) on how to do this. Backflushing is a process where you need to clean water out of the filter system after use. This mainly applies to filters with pumps, tubes, or tubing, and it ensures that the inside of the filter stays dry and clean.
Another consideration here is location: if you are going to be traveling through a desert landscape, there may be few to no trees (a necessity to hang some gravity filters properly). For that type of setting, a different style of filter would be best.
And if you are going to be traveling with a companion or group, the personal LifeStraw filter obviously won’t be the best option (although we love it as a backup!).
This is an important point for ultralight setups and lightweight backpackers. You’ll want to choose a filter that works best for you and how much water you’ll need, but one that can also fit in your pack.
Filters like the Sawyer Squeeze and Katadyn BeFree are popular because the actual filter unit is so small and weighs close to nothing. The Sawyer Squeeze weighs just a couple of ounces, while the Katadyn weighs 6.8 ounces (but remember, it can filter up to 3 L of water at a time).
Filter systems that have water reservoirs and tubing also roll and pack down fairly small. Our personal preference on group trips is a gravity filter system, whereas on solo trips — though they weigh slightly more — our preference is a water bottle filter/purifier, given that we always carry a 1L bottle anyway.
A filter’s lifespan greatly depends on its filter method (cartridge, hollow membrane, chemical, or UV light). Backpacking water filters can last anywhere from 250 to 4,000 L. Cleaning your filter regularly using the methods that the manufacturer recommends will also help prolong its life.
Filters that use a cartridge tend to last anywhere from 200 to 500 L before you need to replace the cartridge. On the other hand, with other filters that last longer, you may need to replace the entire unit at the end of its life. The LifeStraw is an example of this; it can filter around 4,000 L, and then it will stop working and need to be replaced.
For UV methods like the SteriPEN, it’ll last forever as long as you charge or continue to replace the batteries (barring any damage, of course).
Water filters with a filtration element aren’t bulletproof and can fail if allowed to freeze, causing the fragile membranes to break. If this happens, your filter won’t fully treat water passed through it. Thankfully, the workaround is simple: when temperatures look like they’ll dip below freezing, toss your filter in your sleeping bag to keep warm.
If you’ve had a chilly night and forgotten your filter (it happens to the best of us) or potentially dropped it, an integrity test is in order. Filters like the Platypus QuickDraw instruct on how to do this, but the process will work for other hollow fiber filters as well, like the Sawyer Squeeze.
First, backflush a minimum of ½ L of water through the filter, and then empty the dirty water bag and reattach it to the filter. Introduce air into the filter by either squeezing the empty bag or, in gravity filters, by blowing air through the clean side. If air bubbles pass through the other side of the filter element, your filter is compromised and should be replaced.
There’s a bit of a spread when it comes to backcountry water filters, and without a little context, you might be led to believe that more money = more filtration. Instead, consider that there are a number of factors that go into just how much filter you might want to spring for: group size, water quality, and storage needs are just a few.
If you’re solo more often than not and find that day hikes are more your speed, it can be easy to jump into a budget filter that’s quick to deploy and drink straight from the source. Know that these types of ‘straw’ filters won’t give you any storage capacity for the long haul, but for out-and-back endeavors where water is plentiful, they can do the trick.
The LifeStraw Personal ($20) is an excellent example of this, and our fly fisherfolk on staff have come to lean on this filter as a go-to for quick and easy drinking while on the river. Chemical treatments such as Katadyn Micropur ($16) can be cheaper still, but we’d caution that this type of filtration is better suited to some specific use types — such as rivers with high glacial silt content.
Bumping up a bit in price nets you a great deal more in the world of backpacking filters. Even shelling out $40 to $100 can get you a hollow fiber filter that will last for 1,000+ liters and move enough water to make personal trips to refill quick and easy. These filters often offer additional water bladders to filter from and backflushing syringes or hosing to connect to hydration systems.
The Sawyer Squeeze ($39) continues to dominate our recommendations a number of years down the line here, and it’s easy to see why: a decent flow rate, long lifespan, and suite of accessories make this one of the most well-rounded options out today.
The Platypus QuickDraw ($50) is right behind it, and even offers up some additional use options and a quicker flow rate. This price range is also where you can get into some different styles, such as a gravity filter like the Katadyn BeFree Gravity 3L ($75) or Grayl GeoPress ($100) bottle filter.
Going with a premium filter option means that you’ve either got a lot of people to get water to, or are headed somewhere where the water is consistently challenging to filter. Anything north of $100 is likely to either be a pump filter or a complicated gravity system, and will use additional filter elements such as activated charcoal to strip out odors and heavy metals — improving taste.
The MSR Guardian ($390) is the mack daddy of pump filters, and, honestly, it’s a bit overkill for most of North America. That’s why we suggest the MSR MiniWorks EX ($120) as a better option for most folks. The MSR Guardian Gravity Purifier ($300) is similarly overbuilt compared to the pump version and builds on a charcoal filter and 10L (!) capacity to get an entire platoon watered.
The best way to clean your water when backpacking is to use and find the cleanest water source possible. You’ll want to look for clear, running water — somewhere between a babbling brook and a rushing river.
Avoid stagnant ponds or areas where there might be runoff (from livestock, urban areas, etc.) or debris. You’ll also want to find a safe place to refill, pump, or hang your gravity filter.
With some filtering methods, like chemical filters and tablets, you’ll want to wait longer to ensure that the water is clean if it’s below a certain temperature (or cloudy).
Filters most commonly use a tube, pump, or gravity method of filtering. Purifiers use a combination of a tube or chamber with activated carbon or another chemical component to fight against one key difference: viruses.
All of the choices on this list protect against at least bacteria and protozoa, and many also protect against things like toxins, chemicals, and viruses. We recommend choosing the one that will work best based on your situation, budget, and preference.
The lifespan of a filter largely depends on the type of filter. Most hollow fiber or activated charcoal cartridges will need to be replaced every couple hundred uses, or after a certain number of liters have been filtered. Some filters, like the LifeStraw, can last for years, but when it’s run its course you’ll need to buy a new one.
There are also some filters and purifiers that just need new batteries or to be charged.
Yes! Purifiers like the Grayl GeoPress Purifier are built especially to filter and protect against everything you could encounter, whether in the backcountry or in a developing country.
As long as you are following the instructions on your filter or purifier, it will protect against whatever it’s rated for (usually something like 99.999999% of bacteria and 99.999% of parasites and microorganisms).
Our top two considerations when buying gear like this are always: (1) how often we will be using it, and (2) price. Another important factor for many is how long a filter will last. If you backpack or hike 9-12 months out of the year, you probably want to drop more money on a filter that has a longer lifespan.
When all else fails, you can boil water to be safe. But let’s be honest, having a water filter on hand is much better.
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Based in beautiful Chattanooga, Tennessee, Chris Carter is a Senior Editor for GearJunkie, while squeezing in side gigs as an adventure filmmaker and content creator in the outdoor industry. Drawing from his childhood in Africa, experience as a rock climbing and backpacking guide, ultra-marathon running, and years of extensive thru-hiking, he’s passionate about journalism that gets people into the wild. He has thru-hiked the Triple Crown of long trails in America: the Pacific Crest Trail (2018), the Continental Divide Trail (2021), and the Appalachian Trail (2021), and has explored, rock-climbed, and backpacked all over the world. He hopes to spread his love of adventure and travel through his writing, art, and videography.
Mary Murphy has been writing about hiking, running, climbing, camping, skiing, and more for eight years, and has been on staff at GearJunkie since 2019. Prior to that, Mary wrote for 5280 Magazine in Denver while working as an outdoor instructor teaching climbing, kayaking, paddleboarding, mountain biking, and the love of nature to kids. Based in Denver, Colorado, Murphy is an avid hiker, runner, backpacker, skier, yogi, and pack-paddleboarder.
Will is a writer, journalist, and professional misfit based out of the Roaring Fork Valley of Colorado. Will grew up on the Western Slope of the Rocky Mountains, reenacting “Survivorman” episodes and studying books like “Hatchet,” “The Monkey Wrench Gang,” and “Into the Wild.” He’s written on topics ranging from cannabis to local news, the environment and, of course, outdoor gear and adventure. If he’s not banging stories out on his computer, you’ll probably find Will skiing or mountain biking (depending on the season) — or drinking beer at some remote craft brewery.
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