We tested the best backpacking water filters and purifiers for 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 of all, you’ll need a way to get clean and safe water while on the trail.
While we explain more in-depth about how water filters work and how to choose below, 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. Know that 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.
Best Backpacking Water Filters of 2020
Best Overall: Sawyer Squeeze ($37)
This water filter system is the gold standard for many thru-hikers and backpackers across the globe. The Sawyer Squeeze filters down to 0.1 microns, making it effective against bacteria and protozoa (slightly better 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.
What customers said: 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 and drink.
Runner-Up: Katadyn Hiker Microfilter ($52 on Sale)
We chose the Katadyn Hiker because of its great price and performance in the long run. Several users found that it can last for 2-6 years before having to replace the filter.
The Katadyn Hiker filters down to 0.2 microns for bacteria, protozoa, microplastics, and chemicals. The only con? You’ll have to pump it, although the flow rate is good enough even for those who like to keep a quick pace on the trail.
What customers said: 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 waters).
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 ($64 on sale).
Best Budget Filter: LifeStraw ($20)
LifeStraw 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 in the water filter market). 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.
What customers said: The LifeStraw works great, whether you’re going on a day hike or month-long backcountry excursion. Reviewers especially liked how easy it is to pack and carry, and many customers raved about the clear taste on output.
We love this filter for daily adventures and as a backup filter method on longer trips. It also lasts for up to 1,000 L, which is plenty for almost any outdoor adventurer.
Cons: You’ll have to remember to empty the fiber chamber to prevent clogging before storing it away.
Best Gravity Filter: Katadyn BeFree Gravity 3L ($52 on Sale) or Platypus Gravity 4L ($110)
Gravity filters use the always-there 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. Depending on your budget and the size of your group, these are our two favorite options for gravity water filters.
The Katadyn BeFree Gravity filter is the lightest-weight gravity filter on this list at just 6.8 ounces. The Katadyn BeFree holds 3 L 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 back-flushing. Similar to the Sawyer Squeeze, the flow rate is great, and because the bag rolls down, it’s fairly packable.
It came in as a runner-up behind the Sawyer Squeeze largely because it’s more expensive. But for those who don’t mind spending a little more, this is one of our favorite filters that has proven itself over many backpacking and hunting trips in the Rocky Mountains and beyond.
For more, check out our full review of the Katadyn BeFree Gravity Filter.
What customers said: 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. Cons? 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).
This gravity water filter 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 other than drinking (straw filters are great, but not for filtering several liters of water at a time).
The Platypus Gravity system is simple to use and makes filtering water at base camp a cinch. Our biggest con: The filter won’t work in freezing conditions.
What customers said: Although this gravity filter is a different style, most customers found the disconnecting shutoff valves and flow system easy to learn — and reliable to boot.
Other pros: Bags are clearly labeled “dirty” and “clean,” so there’s no confusion, and the overall performance is great. Cons: The filter tends to clog with silty water, and some reviewers wished the seals on the reservoir bags were better.
Best Tablets: Katadyn Micropur ($10-14 per 30-pack)
If you really don’t want to sacrifice weight to a filter, chemical treatment is a great option. Katadyn’s Micropur M1 tablets have been a top choice over the years thanks to their purifying powers and easy-to-use instructions.
Pros: The tablets destroy bacteria, protozoa, and viruses. They are lightweight, fairly budget-friendly, and easy to stash in a pack, pocket, or a first-aid kit.
The only con? You’ll have to wait 4 hours to let the full treatment take effect. (Because of this, we recommend treating your water ahead of time or in larger batches.) These tablets are also a popular backup option.
What customers said: 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.
Best Water Filter Bottles
Lots of us who use water filters for backpacking or hiking also use them for other types of travel — traveling through airports, locally, or abroad. (Bonus: 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.
GRAYL GEOPRESS Bottle ($90)
The GRAYL GEOPRESS uses electroadsorption and activated carbon to purify water. Simply fill, press down, and drink. This is truly the best if you’re drinking from really sketchy or off-grid water sources. The GRAYL protects against heavy metals, chemicals, and viruses in addition to common protozoa and bacteria.
We’ve tested and love this filter for international travel, when you may want to filter all tap water before drinking. In this case, it works wonderfully as a constant companion to keep you hydrated anywhere.
What customers said: Users like its really fast flow rate of 5 L per minute (under 30 seconds to get clean water). The No. 1 complaint is that it’s bulky. Also, the replacement cartridges are expensive and need to be replaced every 250 L.
Although it’s not our favorite for backpacking, it’s a top choice for those traveling in parts of the world with unclean tap water.
LifeStraw Bottle ($36-40)
This is your best bet for a budget option. The LifeStraw bottle uses the same type of hollow-fiber filter as the original LifeStraw but is seamlessly incorporated 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.
What customers said: Similar to the original LifeStraw, customers love that this bottle is easier to use — even easier than just the straw, as the bottle provides a way to carry and store water when you aren’t near a source. Users also love the price point. Other pros: It’s reliable and also works for day-to-day use.
Cons: Some customers have noticed the bottle is prone to leaking, and there is no cover or dust protector for the nozzle on the flip cap. Some customers also wish the carabiner was sturdier for clipping to packs when the bottle is full.
CrazyCap Bottle ($70)
The CrazyCap bottle took home an Innovation award at the Outdoor Retailer trade show, and 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.
What customers said: The UVC light not only protects against viruses and bacteria, but it also sterilizes the bottle (also 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. Cons: It’s not cheap. But if you’re looking for an option that doesn’t involve filters or maintenance, this is a nice choice.
RapidPure Bottle ($60)
While RapidPure is a newer brand, its bottle made our list due to its construction and convenience. The RapidPure Bottle 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 electroadsorption technology to filter out particles 100 times smaller than the standard 0.2 microns.
What customers said: It protects against everything, has a great flow rate, and customers like that it’s easy to use. But the extra $17 each for replacement cartridge makes it a pricier choice.
Best of the Rest
MSR makes a few filters, but this one is our favorite. The MSR MiniWorks EX protects against bacteria, protozoa, heavy chemicals, and particulates. Some of our favorite features of this filter are 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 (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.
Why this didn’t win: The MSR MiniWorks is the heaviest filter out of the ones we considered, and you’ll have to clean it often.
This gravity filter won a spot on this list for its price and lighter weight — at just 6.9 ounces. The LifeStraw Flex Gravity filters down to 0.2 microns and protects against bacteria, protozoa, and microplastics.
It’s also versatile: You can use it as a personal straw, as a gravity filter for groups, or screwed into a standard plastic bottle or bladder. It’s great for solo or group multisport adventures.
Why this didn’t win: 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 up to 2,000 L, the carbon filter portion only lasts 100 L (so you’ll need to buy replacements).
MSR Guardian ($350)
The Guardian filters out nearly everything (including viruses), has an excellent flow rate, and even self-backflushes during use. But for most people, it’s downright overkill.
However, if you’re setting up for a serious adventure that requires filtering a lot of very sketchy water, you may well want to consider forking over the cash.
The Guardian can filter a hefty 2.3 L 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.
For more, check out our full review of the MSR Guardian.
Why this didn’t win: The MSR Guardian is probably one of the “best” 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 $350 and weighs considerably more than other filters.
SteriPEN Adventurer ($75 on Sale)
UV filters are popular for lots 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 made this list for its low trail weight, ease of use, and long lifetime. (The SteriPEN lasts for up to 8,000 treatments.) Pros: It takes up almost no space in your pack and kills viruses, protozoa, and bacteria.
Why this didn’t win: It’s expensive and runs on batteries, which you’ll need to remember to pack for the trail.
How to Choose the Best Backpacking Water Filter
Water filters and water 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). Bacteria is the main concern when you’re drinking out of unsafe water sources in the backcountry or remote areas.
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.
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 viruses.
All of the choices on this list protect against at least bacteria and protozoa, and many also protect against viruses. We recommend choosing the one that will work best based on your situation, budget, and preference.
My top two considerations when buying gear like this are always: (1) how often I will be using it and (2) price. But an important third criterion 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 invest in a filter that has a longer lifespan.
And 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.
Have a favorite backpacking water filter we missed? Let us know in the comments for future updates to this article.