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The Best Backpacking Water Filters of 2023

testing the lifestraw peak series squeeze water filter in a high-alpine creekbed (Photo/Mary Murphy)
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We put the best backpacking water filters and purifiers to the test so you can stay confidently hydrated on your next trip into the great outdoors.

You don’t need much to have a successful backpacking trip. Yes, you’ll need some gear (like a tent, a sleeping bag, and a pack). But most importantly, you’ll need a way to get clean, safe water while on the trail.

Before we explain in depth how each water filter works, here are a few things that will help you through this guide. There are many different methods of filtering (or treating) water. The most common methods are through a cartridge or tube, with either activated carbon, UV light, or chemicals.

Filters also come in different styles: straw-style, pump filters, gravity filters, and UV or tablet treatments. They all make water safe to drink but differ slightly in size, durability, and price.

We’ve spoken to thru-hikers, put many of these to the test, and read hundreds of customer reviews to find out which water filters on the market are truly the best.

Scroll through to see all of our recommended buys or jump to the category you’re looking for. Also be sure to check out the water filter comparison chart at the bottom, our comprehensive buyer’s guide , or our FAQ section for help in snagging the best water filter for you adventurer.

The Best Backpacking Water Filters of 2023

Best Overall Water Filter: Sawyer Squeeze

Sawyer Squeeze Filter System

This water filter system is the gold standard for many thru-hikers and backpackers across the globe. The Sawyer Squeeze ($39) filters down to 0.1 microns, making it effective against bacteria and protozoa (making it slightly more effective and safer than other filters).

It has a great flow rate and comes with a kit to attach to a hydration bladder as well. Thanks to the combination of price and weight, it earns the distinction as the best backpacking water filter.

The Sawyer Squeeze has over 1,000 five-star ratings. Top feedback from customers includes the ultralight trail weight, the ease of use (specifically the reusable roll-up squeeze pouch), and the durability over time.

Many customers love that there are no annoying tubes — you just screw the filter onto the squeeze bag or a bottle (Smartwater bottles work best), and drink. For overall ease of use and durability, this filter has earned its place at the top of the list.

  • Weight: 2.5 oz.
  • Filter type: Bottle/inline filter
  • Filter life: Lifetime warranty
  • Flow Rate: 1.7 L/min
  • Easy to use
  • Lightweight
  • Packable
  • Included pouches aren’t very durable

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Best Budget Water Filter: LifeStraw Personal

Lifestraw Personal

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 only $20.

That said, it’s only good for drinking water directly from the source and doesn’t work for filtering larger quantities into bottles, so it definitely has its limitations. For long-distance backpacking, you’ll probably need a secondary water filtration method. But it’s a great budget pick and solid option for emergency kits, backpacking, hiking, bugout bags, or international travel.

The LifeStraw works great, whether you’re going on a day hike or month-long backcountry excursion. Our reviewers especially liked how easy it is to pack and carry, and we appreciate the clear taste on output.

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.

  • Weight: 1.6 oz.
  • Filter type: Straw filter
  • Filter life: 4,000L
  • Flow Rate: N/A
  • We love this filter for daily adventures and as a backup filter method on longer trips
  • It lasts for up to 1,000 L, which is plenty for almost any outdoor adventurer
  • It doesn’t work for filtering water into a bladder or bottle for reserve (you have to drink as it filters)
  • You’ll also have to remember to empty the fiber chamber to prevent clogging before storing it away

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Best Filter for Thru-Hiking: Katadyn BeFree 0.6L

Katadyn BeFree 0.6 L Water Filter Bottle

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 going the length of trails like the PCT and AT: the Sawyer Squeeze or the Katadyn BeFree ($45).

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, has a lifespan of 1,000 L, and a flow rate of 2 liters 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). Second, it tends to clog a little faster in filthy water than other filters, including the Squeeze.

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.

  • Weight: 2.3 oz.
  • Filter type: Bottle filter
  • Filter life: 1,000 L
  • Flow Rate: 2 L/min
  • Fast flow rate
  • Lightweight
  • Easy to clean
  • Clogs up faster than some models
  • Doesn’t fit as many water bottles as the Sawyer Squeeze

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Best Water-Purifying Tablets: Katadyn Micropur

katadyn micro pur water purifier tablets

If you really don’t want to sacrifice weight for a filter, 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.

Some claim there is a slight aftertaste, although we like these much better than other chemical treatments. Also, many users agree 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.

For backpacking trips, you can use tablets in the evening to ensure that you have clean water for the next day. These are also a great option 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 tablets stashed away for emergencies is smart.

  • Weight: 0.9 oz.
  • Filter type: Chemical purifier
  • Filter life: 1 liter per tab
  • Flow Rate: 1 L/30 min.
  • Destroy bacteria, protozoa, and viruses
  • Lightweight, budget-friendly, and easy to stash in a pack, pocket, or a first-aid kit
  • 4-hour wait time. (Because of this, we recommend treating your water ahead of time or in larger batches.)
  • Expire after 5 years

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Best Gravity Water Filter/Best for Groups: Katadyn BeFree Gravity 3L

Katadyn BeFree 3L Gravity

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. The Katadyn BeFree filters 3L at a time and comes with a quick-connect output hose to easily fill multiple bottles, pots, or bladders.

It also doesn’t require common filter maintenance like backflushing. Similar to the Sawyer Squeeze, the flow rate is great, and because the bag rolls down, it’s fairly packable.

It came in behind the Sawyer Squeeze largely because it’s more expensive. For those who don’t mind spending a little more or are traveling as a bigger group in the backcountry, this is definitely one of the best backpacking water filters available. It’s proven itself over many backpacking and hunting trips in the Rocky Mountains and beyond.

The Katadyn BeFree system can filter smaller particles down to 0.1 microns. The majority of reviewers love that it’s both easy to use and clean.

For more info, check out our full review of the Katadyn BeFree Gravity Filter .

  • Weight: 6.8 oz.
  • Filter type: Gravity Filter
  • Filter life: 1,000L
  • Flow Rate: 2 L/min
  • Requires no backflushing
  • High flow rate
  • You’ll need a place to hang the filter (so if you’re traveling to beaches or deserts, this might not be the best option)
  • Heavy

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Best Water Filter Bottles

Water filters aren’t just great for backpacking and hiking, but can keep you feeling healthy and fresh while road-tripping or traveling abroad. A few of the options below are great for both!

Here are our top choices for travel water filters, whether your adventures take you overlanding, RVing, on day trips, or on international adventures.

Best Overall Water Filter Bottle: GRAYL GEOPRESS Bottle


The GRAYL GEOPRESS ($100) uses electroabsorption and activated carbon to purify water. Simply fill, press down, and drink. It is that fast. (Yes, the convenience, fast filter time, and quality of this filter make it worth the $100.)

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 GRAYL protects 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 may 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, it’s an awesome purification method.

We love its really 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 and need to be replaced every 250 L.

  • Weight: 15.9 oz.
  • Filter type: Bottle filter/purifier
  • Filter life: 65 gallons
  • Flow Rate: 5 L/min
  • Convenient and great for travel
  • Durable
  • Doesn’t just filter water, but purifies it as well
  • More expensive option

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LifeStraw Go Filter Bottle

Lifestraw Go Filter Bottle

This is your best bet for a budget filter bottle. The LifeStraw Go Filter Bottle ($40) uses the same type of hollow-fiber filter as the original LifeStraw but seamlessly incorporates it into a BPA-free plastic bottle. The 22-ounce bottle filters down to 0.2 microns and is a good alternative option to the straw if you won’t be near water sources as frequently.

Similar to the original LifeStraw, we love that this bottle is easy 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 love the price point.

The kit includes an attached carabiner, which comes in handy for storage on the outside of a small travel pack.

  • Weight: 7.8 oz.
  • Filter type: Bottle/straw filter
  • Filter life: 4,000 L
  • Flow Rate: N/A
  • LifeStraw reliability
  • Great for day-to-day use
  • Some customers have noticed the bottle is prone to leaking
  • There is no cover or dust protector for the nozzle on the flip cap

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CrazyCap Bottle

CrazyCap Bottle

The CrazyCap bottle ($65-70) uses UVC light to filter water and even took home an Innovation Award at the 2020 Outdoor Retailer trade show. Initial reviewers like the bottle’s design and the great-tasting water on output.

The 17-ounce purifier bottle is well-suited for those who travel often and want clean water but don’t want to pack filters or treatment tablets in their luggage. We also love that, unlike plastic, this stainless steel bottle is insulated and keeps water colder for longer.

The UVC light not only protects against viruses and bacteria, but also sterilizes the bottle (referred to as self-cleaning) and can be used to sterilize other surfaces. Its rechargeable nature is awesome.

During testing (we used it once each day), we found the cap to last over a week — making it 8 days until it needed a recharge.

If you’re looking for an option that doesn’t involve filters or maintenance (aside from charging), this is a nice choice.

  • Weight: 12.6 oz.
  • Filter type: UVC purifier
  • Filter life: 60 filter cycles per charge
  • Flow Rate: 1 L/90 sec.
  • Sleek
  • Durable
  • Fits in car cupholders as well as pack pockets
  • It’s not cheap
  • Needs to be charged
  • Our bottle has suffered a few dents and dings (still works great!)
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RapidPure Purifier+ Bottle

RapidPure Purifier+ Bottle

While RapidPure is a newer brand, this bottle made our list due to its construction and convenience. The RapidPure Purifier+ Bottle ($52) is a purifier, meaning it protects against viruses, protozoa, and bacteria, making it suitable for travel virtually anywhere.

The bottle uses replaceable cartridges with both activated carbon and electroabsorption technology to filter out particles 100 times smaller than the standard 0.2 microns.

It protects against everything, has a great flow rate, and we love how easy it is to use. But the extra $17 for each replacement cartridge makes it a pricier choice. And we found the plastic cap and shape — especially the base — a bit bulky.

  • Weight: 7.2 oz.
  • Filter type: Bottle/straw filter
  • Filter life: 75 gallons per cartridge
  • Flow Rate: N/A
  • Filters extremely small particles
  • Nalgene-like durability
  • Bulky base doesn’t fit into cup holders or pack sleeves
  • Replacement cartridges are expensive

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Best of the Rest

Platypus QuickDraw

platypus quickdraw

A newer filter system on the market is the small and packable Platypus QuickDraw ($45). 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 or a threaded plastic bottle (like a Smart bottle).

We found it super easy to use and backflush, and we experienced a good flow rate. The filter is good for 1,000L before it needs a replacement.

Factoring in the size, weight, and price, this filter nearly tied for first. 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.

To learn more, check out our in-depth review here .

  • Weight: 3.3 oz.
  • Filter type: Bottle/inline filter
  • Filter life: 1,000 liters
  • Flow Rate: 3 L/min
  • Easy to use
  • Efficient system
  • Budget-friendly
  • Some wish the reservoir was larger

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Katadyn Hiker Microfilter

katadyn hiker microfilter

The Katadyn Hiker ($80) has been one of our long-time favorites 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.

The Katadyn Hiker filters down to 0.2 microns for bacteria, protozoa, microplastics, and chemicals.

Hundreds of users have commented on how well this filter works and how long it lasts. We’ve also found it to work great in subpar conditions (think freezing temps and murky water).

A few reviewers did note, however, that the bulkiness is a downside, and some prefer the quality of the newer model, the Katadyn Hiker Pro ($90). Regardless of which model you choose, the Hiker filter performs great, and the price is right.

  • Weight: 11 oz.
  • Filter type: Pump Filter
  • Filter life: 750 liters
  • Flow Rate: 1 L/min
  • Reliable
  • Doesn’t require replacement filters as often as other choices
  • You’ll have to pump it, although the flow rate is good enough to make up for the lost time.

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LifeStraw Peak Series — Straw Filter & Squeeze Filter

lifestraw peak series

New for 2022, we put the new LifeStraw Peak Series — a personal straw filter, squeeze filter, and gravity filter — to the test this spring. The Peak Series Personal Straw Filter ($20) and Squeeze Filter ($38) 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 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.

  • Weight: Straw: 2.3 oz.; Squeeze Filter: 3.2 oz.
  • Filter type: Straw: straw; Squeeze Filter: bottle/gravity filter
  • Filter life: Straw: 4,000 L ; Squeeze Filter: 2,000 L
  • Flow Rate: Straw: N/A ; Squeeze Filter: 3 L/min
  • Lightweight design
  • Durable and sleek looking
  • On the heavy side
  • Squeeze filter has a shorter filter life than some

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Platypus GravityWorks 4L

Platypus GravityWorks 4L

This gravity water filter ($120) has won a spot on our list for the second 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).

The Platypus GravityWorks system is easy to use and makes filtering significant amounts of water at base camp a cinch. It’s also a great filter choice for car camping along rivers or lakes.

Although this gravity filter is a different style, we found the disconnecting shutoff valves and flow system easy to learn — and reliable as well.

The system also can clog, so this filter requires pretty good cleaning and maintenance.

  • Weight: 11.5 oz.
  • Filter type: Gravity Filter
  • Filter life: 1,500 L
  • Flow Rate: 1.75 L/min
  • Bags are clearly labeled “dirty” and “clean,” so there’s no confusion
  • Overall performance is great
  • The filter won’t work in freezing conditions
  • It tends to clog with silty water
  • Some reviewers wished the seals on the reservoir bags were better

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MSR Guardian Gravity Purifier

msr guardian gravity purifier
(Photo/Tim Newcomb)

With an easy-to-fill 10L reservoir and a 1L per 2 minutes flow rate (which MSR claims is 2.5 times faster than the competition), the new Guardian Gravity Purifier ($270) 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.

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 10L.

This new purifier is up there as one of the best backpacking water filter 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.

Read our full review of the MSR Guardian Gravity Purifier.

  • Weight: 1lb., 3 oz.
  • Filter type: Gravity Filter
  • Filter life: 3,000+ L
  • Flow Rate: 1 L/2 min
  • Works great for group travel in the backcountry
  • Requires no backflushing
  • Purifies the dirtiest of water
  • Pricey
  • Heavy

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MSR MiniWorks EX Water Filter

MSR MiniWorks EX Water Filter

MSR makes a few pump filters, but this one is our favorite. The MSR MiniWorks EX ($110) 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 dromedary bags and Nalgene bottles , so you can easily attach and pump into your drinking vessel.

The filter is ceramic, meaning you clean it over time instead of replacing it (although you may need to replace the tubing). Some users also noted an issue with pressure building up in the filter chamber, causing the flow rate to slow. If you don’t mind pumping, this is still a good filter option.

The MSR MiniWorks is the heaviest filter out of the ones we considered though, and you’ll have to clean it often.

  • Weight: 16 oz.
  • Filter type: Pump Filter
  • Filter life: 2,000 L
  • Flow Rate: 1 L/min
  • Easy to clean
  • Unique carbon/ceramic filter design
  • Pretty expensive
  • Heavy

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LifeStraw Flex Gravity Filter

LifeStraw Flex Gravity Filter

This gravity filter won a spot on this list for its price and lighter weight — just 6.9 ounces. The LifeStraw Flex Gravity ($55) filters down to 0.2 microns and protects against bacteria, protozoa, and microplastics (not viruses).

It’s also versatile. You can use it as a personal straw, as a gravity filter for groups, or screw it into a standard plastic bottle or bladder. It’s great for solo or group multisport adventures.

The flow rate is slower than advertised, and some users had issues with the seal on the bag. And while the hollow-fiber part of the filter is good for up to 2,000 L, the carbon filter portion only lasts 100 L (so you’ll need to buy replacements).

  • Weight: 6.9 oz.
  • Filter type: Gravity Filter
  • Filter life: 2,000 L
  • Flow Rate: 0.5 L/min
  • Affordable
  • Lighter than some other gravity filters
  • Pretty slow flow rate
  • Carbon filter needs to be replaced quite frequently
Check Price at Amazon

MSR Guardian

MSR Guardian Purifier

The Guardian ($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, you may want to consider forking over the cash.

The Guardian can filter a hefty 2.3L per minute and 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.

Check out our full review of the MSR Guardian .

  • Weight: 17.3 oz.
  • Filter type: Pump filter/purifier
  • Filter life: 10,000 L
  • Flow Rate: 2.5 L/min
  • Self-cleaning
  • Super long filter life
  • Fast flow rate
  • Heavy
  • Expensive

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SteriPEN Adventurer

SteriPEN Adventurer

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).

The SteriPEN ($105) made this list for its low trail weight, ease of use, and long lifetime. (The SteriPEN lasts for up to 8,000 treatments.) It’s also very small and packable, which makes it great for quick outings where you don’t want to carry extra water.

The downside is it’s expensive and runs on batteries, which you’ll need to remember to pack for the trail.

Check out our full review of the SteriPEN Adventurer

  • Weight: 3.6 oz.
  • Filter type: UV purifier
  • Filter life: 8,000 L
  • Flow Rate: 1 L/90 sec
  • Lightweight
  • Easy to use
  • Long lifetime
  • Have to keep it charged
  • Pricey

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Water Filters Comparison Chart

Water Filters Price Weight Filter Type Filter life Flow Rate
Sawyer Squeeze $39 2.5 oz. Bottle/inline filter Lifetime warranty 1.7 L/min
LifeStraw Personal $20 1.6 oz. Straw filter 4,000L N/A
Katadyn BeFree 0.6L $45 2.3 oz. Bottle filter 1,000 L 2 L/min
Katadyn Micropur $16 0.9 oz. Chemical purifier 1 liter per tab 1 L/30 min
Katadyn BeFree Gravity 3L $75 6.8 oz. Gravity Filter 1,000L 2 L/min
GRAYL GEOPRESS Bottle $100 15.9 oz. Bottle filter/purifier 65 gallons 5 L/min
LifeStraw Go Filter Bottle $40 7.8 oz. Bottle/straw filter 4,000 L N/A
CrazyCap Bottle $65-$70 12.6 oz. UVC purifier 60 filter cycles per charge 1 L/90 sec
RapidPure Purifier+ Bottle $52 7.2 oz. Bottle/straw filter 75 gallons per cartridge N/A
Platypus QuickDraw
$45 3.3 oz. Bottle/inline filter 1,000 liters 3 L/min
Katadyn Hiker Microfilter $80 11 oz. Pump Filter 750 liters 1 L/min
Straw Filter & Squeeze Filter $20 and $38 Straw: 2.3 oz.; Squeeze Filter: 3.2 oz Straw: straw; Squeeze Filter: bottle/gravity filter Straw: 4,000 L ; Squeeze Filter: 2,000 L Straw: N/A ; Squeeze Filter: 3 L/min
Platypus GravityWorks 4L $120 11.5 oz. Gravity Filter 1,500 L 1.75 L/min
MSR Guardian Gravity Purifier $270 1lb., 3 oz. Gravity Filter 3,000+ L 1 L/2 min
MSR MiniWorks EX Water Filter $110 16 oz. Pump Filter 2,000 L 1 L/min
LifeStraw Flex Gravity Filter $55 6.9 oz. Gravity Filter 2,000 L 0.5 L/min
MSR Guardian $390 17.3 oz. Pump filter/purifier 10,000 L 2.5 L/min
SteriPEN $105 3.6 oz. UV purifier 8,000 L 1 L/90 sec

Why You Should Trust Us

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 took a look at 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.

Buyer’s Guide: How to Choose a Water Filter

The LifeStraw Peak Series squeeze filter next to an alpine stream
Testing the LifeStraw Peak series in a high-alpine stream; (photo/Mary Murphy)

Water filters and water purifiers work in similar ways, but it’s helpful to know the difference when choosing.

Filters vs. Purifiers

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 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.

Filter Time and Flow Rate

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 1-3 L 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!).

Packed Size

This is an important point for ultralight 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 the weight is 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.

Durability and Longevity

The lifespan of a filter 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.

Ones 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 CrazyCap filter bottle and SteriPENs , they’ll last forever as long as you charge or continue to replace the batteries (barring any damage, of course).

Woman Using LifeStraw Personal Water Filter in Stream


What Is the Best Way to Purify Water When Backpacking?

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).

What's the Difference Between Filtration and Purification?

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.

How Long Does a Backpacking Water Filter Last?

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 LifeSt raw , 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.

Can Viruses Be Filtered Out of Water?

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).

dipping the grayl press water purifier into a clear mountain stream
(Photo/Mary Murphy)

How Much Should I Spend?

My top two considerations when buying gear like this are always: (1) how often I 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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