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Water Filter Score Weight Type
Top Pick: Katadyn Hiker
11 oz Pump
Best for Groups: Platypus GravityWorks 4L
11.5 oz Gravity
Best for Individuals: Katadyn BeFree
2 oz Squeeze
MSR MiniWorks EX Microfilter
16 oz Pump
Best Value: Sawyer Squeeze
3 oz Squeeze/Inline
Sawyer Micro Squeeze
2 oz Squeeze
Sawyer Mini
2 oz Squeeze
1.6 oz Direct
Steripen Adventurer Opti
4 oz UV Light
Aquamira Water Treatment Drops
2 oz Chemical

We put 10 of the best backpacking water filters and purifiers to the test. After months of field use and tests, we determined that the Katadyn Hiker was our all-around Top Pick. It’s convenient, easy to use, and filters large volumes of water quickly.

For larger groups, we absolutely love the Platypus GravityWorks 4L. For individuals, the Katadyn BeFree was our favorite. Finally, if you want a versatile filter at a great price, the Sawyer Squeeze won our Best Value award.

Read on for our full reviews and for advice on choosing the best backpacking water filter or purifier for your next trip.

The 10 backpacking water filters and purifiers we tested.
The 10 backpacking water filters and purifiers we tested.

Top Pick: Katadyn Hiker

Katadyn HikerThe Katadyn Hiker is our top all-around pick. It’s versatile, intuitive to use, and quick to set up and start filtering.

Katadyn claims a flow rate of 1 liter per minute, and based on our tests that’s pretty much spot on. Filtering one liter, including setup time, took just over a minute and a half. This filter was by far the quickest at filtering 4 liters, at a little under 5 and a half minutes.

We loved the versatility of this pump. It includes two adapters, one for water bottles and one for water bladders.

The bottle adapter fits on a wide-mouth Nalgene (although we would have liked a slightly more secure fit as it had a tendency to pop out while we were pumping). The water bladder adapter snaps into the hose attachment of most water bladders (we tested it on a Camelbak and an Osprey).

One drawback with this filter is that replacement filter cartridges are pricey, and in our experience the filters don’t last quite as long as some other brands. We have also seen some reviewers complain that the plastic hose attachments can break off, although we used the Hiker extensively and never had this issue.

11 oz may be a touch on the heavy side for solo or ultralight backpackers, but the trade-off in convenience, ease of use, and speed is more than worth it for those who aren’t counting ounces.

Product Specs

  • Weight: 11 oz
  • Group Size: 1-2
  • Filter/Purification Mechanism: Glassfiber/carbon filter

Best Backpacking Water Filter for Larger Groups: Platypus GravityWorks 4L

Platypus GravityWorks 4LFor capacity and convenience, nothing beats the Platypus GravityWorks 4L.

Although the GravityWorks was one of the slower filters, nearly all of that time is passive. No pumping or stirring — just relax, enjoy the scenery, and let gravity do all the work for you.

It was the slowest in our test at filtering just one liter, but it’s made to be a higher capacity filter. Once you get to 4 liters, it’s about on par with the pump filters.

Although we didn’t test the time to filter 8 liters, we’d bet that this would be by far the fastest to get you that quantity of clean water.

The GravityWorks also has an amazing amount of storage. Each bag has a 4-liter capacity. This means with the clean water bag full and the dirty water bag ready to go, you can have 8 liters of water on tap at camp. We never realized how much of a luxury that was until we used the GravityWorks.

It’s not perfect, though. Finding a place to hang the bags can be tricky, and we worried that the plastic would tear while we were trying to maneuver it through tree branches to find the perfect spot. It seems fairly durable, though. We never had any issues.

Trying to fill the dirty water bag in a pond or small stream is tricky. If your water source isn’t a decent-sized stream, filling the bag can be tedious and frustrating. It’s difficult to get it to zip closed securely.

For smaller groups of backpackers trying to move fast, this isn’t the best option. It’s not the quickest way to filter a couple of liters on the go. But for larger groups, or for backpackers who like to base camp in a spot for a couple of days, this is one of the most convenient ways to have readily available clean water around camp.

Platypus GravityWorks set up in the branches.
Platypus GravityWorks set up in the branches.

Product Specs

  • Weight: 11.5 oz
  • Group Size: 2-4
  • Filter/Purification Mechanism: Hollow fiber filter

Best Personal Backpacking Water Filter: Katadyn BeFree

Katadyn BeFreeFor filtering water on the go, the Katadyn BeFree quickly became our go-to. This tiny, easy-to-use filter weighs just 2 oz and fits just about anywhere.

We also loved how the filter sits inside of the bottle, making it easy to use and carry. Other personal filters that we tested stuck out from the top of the bottle, requiring juggling a separate cap for the bottle or carrying around an awkward apparatus. The Katadyn BeFree felt more streamlined and enjoyable to use.

It was one of the quickest water filters in our test, taking just under a minute to filter a liter of water. Whether drinking directly from the bottle or using it to squeeze water into a Nalgene, the malleable bottle was the easiest to handle and squeeze.

The filter is incompatible with most other water bottles and containers, unfortunately. If you want to switch out the included container for something larger, as of this writing you’re limited to Hydrapak’s collapsible water containers.

The unique filter requires little maintenance — cleaning it is as simple as swishing some water around in the bottle to dislodge any particles.

We recommend doing this often to maximize the lifespan of the filter. Reports of the flow rate decreasing greatly over time abound. After a summer of field testing we’ve yet to experience a substantial decrease in flow rate, but we’ll update this review should that change.

Overall, this is an awesome filter that we loved throwing in our packs for long days on the trail or for quick fill-ups when we didn’t want to break out a full treatment system.

Product Specs

  • Weight: 2 oz
  • Group Size: 1
  • Filter/Purification Mechanism: Hollow fiber filter

Best Value: Sawyer Squeeze

Sawyer SqueezeThe Sawyer Squeeze easily won our Best Value award. It’s lightweight, simple to use, versatile, and incredibly affordable.

We tested three different squeeze-style filters from Sawyer, and this was our favorite. It had the quickest flow rate and was the easiest to squeeze water through.

Sawyer wins versatility points over the Katadyn BeFree. This filter is compatible not only with numerous brands of collapsible water bottles, including Evernew and old Platypus containers, but also with most plastic water or soda bottles.

The Squeeze is definitely a little awkward to drink from, with the filter sticking out on top of the water bottle. We also found that Sawyer’s included collapsible bottles weren’t as easy or enjoyable to use as Katadyn’s more flexible bottle.

Those are minor gripes, though. The versatility and quality that you get for a relatively low price blew us away. The Squeeze is an easy choice for our Best Value award.

Product Specs

  • Weight: 3 oz
  • Group Size: 1
  • Filter/Purification Mechanism: Hollow fiber filter

Reviews of the 6 Other Backpacking Water Filters & Purifiers We Tested

MSR MiniWorks EX Microfilter

MSR MiniWorks EX MicrofilterThe MSR MiniWorks EX Microfilter is a relatively burly backpacking filter with a ceramic and carbon medium that produces clean, clear, taste-free water.

We love that the filter is easy to clean and maintain in the field, though it requires fairly regular cleaning.

MSR claims a flow rate of 1 liter per minute, but we were far from that in our tests. Pumping four liters of clear water felt tedious, even after stopping to clean the filter.

We counted over 70 pumps per liter, compared to around 50 pumps per liter for the Katadyn Hiker. The pump also required more force than the Katadyn Hiker, making pumping water into a bit of a chore.

Another minor gripe is the lack of versatility or compatibility with water containers. The filter screws neatly onto a Nalgene and MSR’s water bladders, but it’s difficult and awkward to filter water into anything else.

Ceramic filters typically last longer than other types. If you filter a lot of water, this may be a better long-term value than other pump filters. If you’re willing to put up with a little more work and maintenance, this filter is still a great option.

Filtering water from a stream with the MSR MiniWorks EX Microfilter.
The MSR Microfilter works well with Nalgenes but few other containers.

Product Specs

  • Weight: 16 oz
  • Group Size: 2-4
  • Filter/Purification Mechanism: Ceramic and carbon

Sawyer Micro Squeeze

Sawyer Micro SqueezeWe were impressed with how well the tiny Micro Squeeze worked.

It weighs the same as the Sawyer Mini, but it was substantially faster at filtering and easier to drink through (though the larger Squeeze still beat it out). It’s the least awkward of the three Sawyer filters to drink from, thanks to its shorter design.

The Sawyer Squeeze just barely inched ahead and took our Best Value award because of its versatility and better flow rate. But the Micro Squeeze is still a good option for a compact and inexpensive filter.

Product Specs

  • Weight: 2 oz
  • Group Size: 1
  • Filter/Purification Mechanism: Hollow fiber filter

Sawyer Mini

Sawyer MiniOverall, we liked the compact and slim design of the Sawyer Mini. It has the benefit of being slightly less awkward and top-heavy than the Sawyer Squeeze when attached to a water bottle.

However, it was the slowest of the individual filters, and the most difficult to squeeze water through.

It’s also the least expensive, so if you are looking for the cheapest way to filter your water and don’t mind putting in more effort, it’s a great product.

If you can spend a few extra bucks on the Micro Squeeze or the Squeeze, though, we’d recommend those for their better flow rate.

Product Specs

  • Weight: 2 oz
  • Group Size: 1
  • Filter/Purification Mechanism: Hollow fiber filter

Long-Term Testing Notes

99Boulders owner and editor Alex Beale has been using the Sawyer Mini for the past two years. He’s used it on backpacking trips across the country, from the Appalachian Trail in Georgia to the Grand Staircase-Escalante National Monument in Utah.

It’s incredibly compact and lightweight, he says, and notes that it’s worth considering if you’re trying to go ultralight.

His main gripe — consistent with our field testing results — is the low flow rate. It was acceptable at the start, he says, but it quickly decreased to be quite slow. He’s recently switched to a Sawyer Squeeze for the better flow rate, and now thinks the Squeeze is a better alternative for most hikers.


LifeStrawWith no storage capacity or ability to pump water into another container, the LifeStraw has limited usefulness and definitely isn’t meant to be a primary water filter.

Still, we were impressed with this simple little device. It’s as easy to use as any straw. Simply pop off the caps, dip one end into a water source, and drink.

We found it easy to drink through, with little resistance, and we never noticed any sediment getting through even in some fairly murky ponds.

Lifestraw claims their products can filter up to 4,000 liters and last for up to 5 years before needing replaced. At only 2 oz, and with no parts to fail, break, or lose, we think the LifeStraw is a good emergency backup if your primary water treatment mechanism fails.

Product Specs

  • Weight: 2 oz
  • Group Size: 1
  • Filter/Purification Mechanism: Hollow fiber filter

Steripen Adventurer Opti

Steripen Adventurer OptiThe Steripen is unique in the water filter world. It’s not a water filter, but a UV water purifier. It uses UV light to disrupt the replication of bacteria and viruses, rendering them harmless.

It’s also effective against viruses, which are too small for most filters. While viruses typically aren’t an issue for backpackers in North America, if you are traveling internationally this can be a lifesaver.

The Adventurer Opti certainly has its drawbacks. While it is lightning fast for filtering a liter or two along the trail, it gets tedious to filter larger quantities of water. It also only works with a hard-sided bottle of 1 liter or smaller.

What’s more, the Adventurer Opti model in particular is only compatible with wide-mouth water bottles such as a Nalgene. It won’t fit inside standard-mouth bottles such as smartwater bottles. (A different model, the Steripen Ultra, is compatible with smartwater bottles.)

As with any electronic device, Steripens can be finicky. The Adventurer Opti has overheated on us when purifying large amounts of water. We had to take the batteries out to let it cool down.

Of course, batteries die. You’ll need to bring backups or at least a backup filter/purifier if this is your main way to purify your water.

The Adventurer Opti also has a complex code of red and green flashes to signify everything from low batteries, to the lamp being broken, to a successful cycle of purification. We were often left guessing at what the Steripen was trying to tell us.

While it doesn’t have a waterproof rating, we’ve accidentally dropped ours in a liter of water. When we pulled it out after about 5 seconds, the battery compartment was completely dry and the device suffered no ill effects.

Despite these reliability concerns the Steripen has never let us down. We’ve used it with some questionable water sources, too.

For minimalists and solo backpackers, or for international travelers, the Steripen is a fantastic little gadget — one we recommend for those who understand and don’t mind the drawbacks.

The compact size of the Steripen Adventurer Opti
The wide base of the Adventurer Opti is only compatible with wide-mouth water bottles like Nalgenes.

Product Specs

  • Weight: 4 oz
  • Group Size: 1-2
  • Filter/Purification Mechanism: UV light

Aquamira Water Treatment Drops

Aquamira Water Treatment DropsAquamira is extremely simple to use — just mix equal parts of Part A and Part B in the cap provided and add it to your water.

Aquamira recommends waiting 5 minutes for the chemicals to activate before adding them to your water, and another 15 minutes (minimum) for the treatment to work.

20 minutes is a long time to wait for water to be ready, so it wasn’t our preferred choice when trying to cover a lot of distance or refill quickly from steams along our route.

The taste wasn’t as bad as we’d expected, and not as bad as some water purification tablets, but it was noticeable. We found ourselves missing that crisp taste of fresh mountain water.

As with any water purifier, this won’t remove any sediment from your water, so you should be prepared to pair your Aquamira with a prefilter if necessary.

Despite the drawbacks of Aquamira, there’s no denying that it is effective. We know backpackers who swear by Aquamira and have used it on many international trips where water contamination and viruses are a major concern.

If you have the time to wait for your water to be purified, Aquamira drops are a reliable way to get safe drinking water just about anywhere.

Product Specs

  • Weight: 2 oz
  • Group Size: 1-2
  • Filter/Purification Mechanism: Chlorine dioxide


Here are the best backpacking water filters and purifiers:

  • Katadyn Hiker
  • Platypus GravityWorks 4L
  • Katadyn BeFree
  • MSR MiniWorks EX
  • Sawyer Squeeze
  • Sawyer Mini
  • Sawyer Micro Squeeze
  • Lifestraw
  • Steripen Adventurer Opti
  • Aquamira Water Treatment Drops

How to Choose the Best Backpacking Water Filter or Purifier for Your Needs

Types of Backpacking Water Filters & Purifiers

Pump filters – With these filters, you manually pump water from a water source through a filter typically made of hollow fibers or ceramic. These tend to be heavier and bulkier than other options, but for many backpackers, the ease of use and reliability makes up for the weight penalty.

Gravity filters – These work similar to pump filters, except that gravity does all the work. Gravity filters usually take a little bit longer than pump filters, but they involve much less work and are great for large quantities of water.

Individual filters – Designed to fit onto a water bottle or to drink directly from a water source, these small filters are compact, simple, and perfect for getting clean water on-the-go. They don’t have a very high capacity or much ability to store water. You typically either squeeze or suck water through them directly into your mouth or another water bottle.

Chemical purifiers – Using either iodine or chlorine dioxide, chemical purifiers involve adding a small amount of chemicals to your water. Eventually, these chemicals will kill anything in the water, while remaining safe for you to drink. Although they are incredibly light and compact, chemical purifiers take a long time to work (at least 15 minutes for 1 liter, and longer to kill off everything). They can also leave an unpleasant chemical taste in water. For most backpackers, this is a backup or last resort method of water treatment.

UV light purifiers – Relatively new the the water treatment world, these gadgets use UV light to disrupt the replication of bacteria and viruses, rendering them harmless. They are fairly quick and easy to use for small quantities of water, but they have the drawback of relying on batteries and finicky electronics.

Filters vs. Purifiers

Water treatment methods fall into one of two categories: filters or purifiers.

Water filters force the water through a medium that filters out particles over a certain size. They typically catch most bacteria, cysts, and protozoa, but they aren’t effective against viruses. Filters are typically quicker and better for murky water sources.

Water purifiers don’t remove anything from the water. Instead they use either chemicals or UV light to kill or render harmless any bacteria or viruses in the water. Purifiers are better for more heavily contaminated water sources and for international travel, where viruses are a concern.

Your Water Source

Cleaner water: If the water sources for your trip will be primarily pristine, untouched alpine streams, then just about any filter or purifier will do.

Questionable or sediment-laden water: If you expect to be getting your water from murky ponds or potentially contaminated sources, you’ll want to get a filter that can handle murky water. You may want to avoid purifiers as they won’t do anything to clear out sediment. Or pair your purifier with a prefilter such as a bandana or coffee filter to remove as much sediment as possible.

Locations with viruses: Also consider where you’ll be doing your backpacking. In North America, viruses like norovirus and Hepatitis A typically aren’t concern. In many places overseas, these and other viruses can pose a risk to backpackers. If you are traveling internationally, a chemical or UV purifier, or a filter with pores small enough to capture viruses, is your safest bet.

How We Tested

Ease of Set-Up & Use

We assembled and disassembled each pump multiple times, both in the field and at home. We considered, how quickly we could get it set up, how intuitive it was to use, and the difficulty and frequency of maintenance required.

Flow Rate Test

We wanted to know how quickly each pump could filter water, so we timed how long it took to filter one liter of water

Note: We did not include the LifeStraw in this test because there’s no way to filter water into another container with it.

Field Testing

We used these water filters and purifiers in the field on our backpacking trips for a summer, testing them in a variety of conditions from murky ponds to clear alpine streams.

Drinking through the Sawyer Mini.


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