Best Backpacking Water Filters & Purifiers of 2023

JUMP TO: SAWYER SQUEEZE | KATADYN BEFREE | AQUAMIRA WATER TREATMENT DROPS | SAWYER PERSONAL WATER BOTTLE | STERIPEN ULTRA | MSR GUARDIAN PURIFIER | SAWYER MICRO SQUEEZE | BUYING ADVICE

Author: Steve Edgerton | Updated: Oct 10, 2023
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The Short Version

The Long Version

Water filtration and treatment is a critical component of every backpacker’s kit. There are few things less pleasant — and potentially life threatening — than a bout of giardia when you’re days away from civilization.

From UV lights, iodine tablets, packable filter systems, and beyond, the options for water treatment are endless.

To help you find the best option, we have reviewed our favorites – breaking down weight, flow rates, ease of use, and what unpleasant things each device actually filters out of your water.

If you love reading this review of the best backpacking water filters and purifiers, then you'll likely love reading some of our other hiking and backpacking content:

Need To Know What To Look Out For?

Need some more information on the filtration features to pay attention to? Check out our buying advice at the bottom of the page. We take a deep dive into the key components of treatment devices and the water sources and adventures they are best for.

Best Overall: SAWYER SQUEEZE

FILTER MATERIAL/ACTIVE INGREDIENT: Hollow Fiber

FILTER METHOD: Squeeze

WEIGHT: 5.7 oz

FLOW RATE: 1.7 L/min

PRICE: $$

PROS: Lightweight, durable, and easy to use

CONS: Not great for larger groups, does not protect against viruses, chemicals, heavy metals

The Sawyer Squeeze has established a cult following amongst the ultralight community, and for good reason. It weighs less than 6 ounces, has a decent flow rate, and is easy to use.

A minimal design with few components means fewer opportunities for failure when out in the backcountry. Each filter can treat hundreds of thousands of liters of water before needing replacement, making it our durable favorite for thru hikes and consistent use.

You can use the filter alongside the included pouch, attach it right onto another compatible water bottle, or even right onto a bladder hose. It also comes with a syringe to easily backflush the filter and remove sediment build-up.

The hollow fiber filter offers a 0.1-micron pore size. Like most filters, this works for filtering out bacteria and protozoa, but will not remove viruses, chemicals, or heavy metals.

Best Allrounder: KATADYN BEFREE

FILTER MATERIAL/ACTIVE INGREDIENT: Hollow Fiber

FILTER METHOD: Gravity

WEIGHT: 4 oz with 3L bladder

FLOW RATE: 2L/min

PRICE: $$

PROS: Quick flow rate, easy to clean, packable, filter compatible with multiple bladder sizes

CONS: Shorter filter life, does not protect against viruses, chemicals, heavy metals

The Katadyn BeFree filter may not do anything the best, but it is really, really good at just about everything. With a quick flow rate, modest weight, and super packable design, the BeFree is a great option for most backcountry adventures.

The hollow fiber filter effectively treats bacteria and protozoa. It is easy to clean too: just swish it in flowing water to remove any sediment buildup, no Sawyer-style syringes or backflushing necessary. Its gravity filter has an excellent flow rate of 2 L/min, keeping downtime on the trail to a minimum.

The major downside to the BeFree is the filter life. They tend go quick, only being good for about 1000 L compared to the advertised 378,000 L for a Sawyer Squeeze. The upshot is that the filters are relatively affordable and can be purchased on their own.

They are also compatible with a variety of bladder sizes, from 0.6 L to 6 L, making the BeFree a versatile, trustworthy choice for both solo missions and large group outings.

FILTER MATERIAL/ACTIVE INGREDIENT: Chlorine Dioxide

FILTER METHOD: Chemical Treatment

TREATMENT TIME: 20-30 mins

WEIGHT: 3 oz

PRICE: $

PROS: Affordable, lightweight, kills all waterborne pathogens

CONS: Affects taste, longer sterilization time, chemical treatment

For the pack weight-conscious, it is hard to go much lighter than treatment drops. The Aquamira Water Treatment Drops are easy to use and highly effective, eliminating the risk of protozoa, bacteria, and viruses. One 3-ounce kit will treat 114 L of water, good for everything but the longest of unsupported trips.

Treatment drops are ultralight, and you don’t have to worry about breakages or maintenance. However, you pay for those advantages in other ways. Full sterilization takes 20-30 minutes and they will not filter out any sediment. The drops can also leave a taste that some may find unpalatable.

Despite being a chemical treatment, chlorine dioxide is completely safe to take regularly, unlike iodine—another common water treatment option. The Aquamira drops are best for trips where clear, sediment free water is abundant and as an affordable, ultralight option for international travel.

Best Water Bottle Filter: SAWYER PERSONAL WATER BOTTLE

FILTER MATERIAL/ACTIVE INGREDIENT: Hollow Fiber

FILTER METHOD: Straw

WEIGHT: 5.5 oz

FLOW RATE: 1.7 L/min

PRICE: $$

PROS: Integrated bottle and filter is easy to use

CONS: Greater weight to volume ratio than filter and bladder combinations

The Sawyer Personal Water Bottle borrows the same filter design of Squeeze fame, integrating it right into a drinking vessel—just fill up and go.

It holds 34 ounces, and, like other Sawyer products, the 0.1-micron filter effectively treats against bacteria and protozoa. We love this filter for its durability—they are designed to filter 100,000 L over their lifetime.

The ease-of-use makes water bottle filters great for short trips or day hikes in which you anticipate needing to fill up on water, but you do pay for the convenience with some added bulk. Thru-hikers and ultralight enthusiasts who prefer filters over chemical treatment would be better served by combining the Sawyer Squeeze with a lightweight bladder or bottle. Read our full review here.

Best for Travel: STERIPEN ULTRA

FILTER MATERIAL/ACTIVE INGREDIENT: UV Treatment

TREATMENT TIME: 90 seconds

WEIGHT: 6.7 oz

PRICE: $$$

PROS: Lightweight, eliminates all pathogens

CONS: Must rely on battery, doesn’t filter sediment or microplastics, expensive

The SteriPen Ultra is a UV filter that shines on international trips where water quality is constantly a risk. The lightweight, rechargeable device uses ultraviolet light to kill off bacteria, protozoa, and viruses.

Treatment takes about 90 seconds, and unlike chemical-based treatments, there is no funny aftertaste. Of course, UV treatment doesn’t filter out sediment from the water – so if you think you’ll be encountering turbid water then it’s best to also carry a pre-filter.

The pen features a rubber seal, allowing you to tip your bottle upside down, then move and shake your bottle to ensure full exposure to the UV rays. It’s worth pointing out that this isn’t the case for all SteriPen products – e.g. the SteriPen Adventure Opti has an awkward shape and no rubber seal, meaning it requires a wide-mouth bottle or vessel to work on the trail.

You can treat up to 50 L of water per charge, but the battery tends to be less dependable in cold weather. We like the SteriPen Ultra for travel because, assuming semi-regular access to power, it will outlast filters or drops. It is expensive, but offers an ultralight and highly effective method for water treatment that travelers will appreciate having as an option.

Best for Turbid Water: MSR GUARDIAN PURIFIER

FILTER MATERIAL/ACTIVE INGREDIENT: Hollow Fiber

FILTER METHOD: Pump

WEIGHT: 20.5 oz

FLOW RATE: 1.7 L/min

PRICE: $$$

PROS: Durable, reliable, can filter even the most questionable water sources

CONS: Heavy, bulky, very expensive

The MSR Guardian Purifier is built like a tank, with all the good and not so good characteristics that the comparison suggests.

The filter, pump, and other components are incredibly durable to the point of being basically bombproof. It effectively filters even the most sediment-laden water you will hope to ever encounter, thanks in large part to its easy-to-use built-in backflushing system. The filter is also resilient to freezing, making the Guardian a reliable option in colder climates.

This filter is a serious investment though. It is many times more expensive than other treatment options covered here. At over 20 ounces and with a bulky profile, it is probably overkill for many hikers and backpackers too.

But for remote trips with questionable water sources, where durability and reliability are top priorities, the MSR Guardian Purifier is the way to go. Read our full review here.

Best on a Budget: SAWYER MICRO SQUEEZE

FILTER MATERIAL/ACTIVE INGREDIENT: Hollow Fiber

FILTER METHOD: Squeeze

WEIGHT: 3.8 oz

FLOW RATE: 0.65 L/min

PRICE: $

PROS: Lightweight, inexpensive, durable

CONS: Included bladder breaks easily, slower flow rate

The Sawyer Micro Squeeze is an ultralight, ultra-affordable filtration option. Best suited for solo use, the Micro Squeeze is like its full-size counterpart in the durability of its filter, just in a smaller, lighter package.

Along with the hollow fiber filter, the Micro Squeeze comes with a 1 L pouch, a straw, and a syringe for backflushing. It shines as an on-the-go filtration system, drinking through the filter from a bottle or attaching it to a dedicated hydration bladder. It can also attach onto any water bottle with standard threading, making it extra versatile. Alternatively, you can use the included pouch and pre-filter into a bottle at the water source.

A downside of the Micro Squeeze worth noting is that the filter can clog with sediment quickly. We recommend that you backflush with the included syringe every time you fill up. This can feel tedious, and you need to bring the syringe on any multi day trips, but considering the performance you get relative to this filter’s modest price, it is well worth it.

If you can’t decide between the Squeeze and the Micro Squeeze, check out our in-depth comparison.

BUYING ADVICE FOR WATER FILTRATION DEVICES

Not all water filters are made equal, and neither are all water sources. The best water treatment device often depends on the nature of your trip—the length, the season, and the overall quality and variability of the water sources you will encounter.

Here are the key things to consider that will help in picking the best treatment option for your next trip.

Filter Method

Water filters and treatments differ by the mechanism in which they purify water. Options generally include:

FILTERS: Typically made from hollow fiber, filters are an ultrafine, semi-permeable membrane that remove most pathogens that commonly plague backpackers, like giardia and cryptosporidium, along with microplastics.

Filters can use gravity, straws, squeezing, or a pump to transport water through the filter. Most are not fine enough to remove viruses, heavy metals, or chemicals, but in wilderness settings these contaminants are rarely a big issue.

 

It adds a bit of bulk over just carrying the filter, but the Sawyer Personal Water Bottle is a solid option for day hikes and short outings where you want a quick-and-easy water filtering solution.

 

CHEMICALS: Chemical treatments are extremely light and highly reliable. The downside is they tend to result in strange tasting water and sterilization can take 20-30 minutes, requiring some advanced planning. But they can be great to have as a backup, or even as your only filtration method if you are keen on moving fast and light in landscapes with clear, sediment-free water.

If you rely on chemical treatment regularly, look for products with chlorine dioxide rather than iodine, as too much iodine can potentially be harmful.

UV LIGHT: Ultraviolet rays eliminate viruses, bacteria, and protozoa from water sources. They are light and easy to use, making them a favorite among international travelers and backpackers. Being battery powered is often a failure point though, and they tend to run out of charge quick in colder climates.

Another downside is that UV lights do not remove sediment from the water, unlike a filter. And worse, the sediment in turbid water can actually reduce the effectiveness of the UV treatment. So, UV lights are also best suited to clear, sediment-free water – or you can pre-filter your water beforehand.

 

UV lights like the SteriPen range are light, easy to use, and eliminate viruses – making them great for travel – but they do require batteries and don’t filter sediment from water making them less versatile in wilderness environments.

 

Durability

The last thing you want is to be deep in the backcountry with a filter that is no longer functional. All treatment option will have a weak point, whether it is being prone to clogging or freezing, leaking storage vessels, or dead batteries. The length of your trip and the quality of the water sources available should be considered to get the most out of your filter.

CLOGGING: For example, highly turbid water sources—like the famous Colorado River that weaves through the Grand Canyon, or the milky green glacial streams high in the Rocky Mountains—will clog up an otherwise durable squeeze filter almost immediately. A pump filter with a backflush mechanism will fare much better.

 

Filters like the Sawyer Squeeze come with a syringe for backflushing, which is critical to maintaining performance when using the filter with highly turbid water sources.

 

FREEZING: Many filters will not operate effectively after being frozen – when water expands during freezing it will likely damage the hollow fibers of the filter, rendering the filter ineffective.

When camping in cold temps you should try to keep your filter warm overnight – sealing it in a plastic bag and keeping it inside your sleeping bag is a good trick. Alternatively, consider taking a filter that can handle freezing, such as the MSR Guardian.

SQUEEZE POUCHES: Some squeeze style filters come with pouches that allow you to easily squeeze water through the filter at high pressure. But be wary that these pouches are often the first point of failure – e.g. splitting open. If you are heading into the backcountry with a squeeze filter, then consider carrying a backup pouch or use the filter with a compressible but more durable water bottle like the Hydrapak Flux.

CONSIDER CARRYING A BACKUP OPTION: Overall, the most durable treatment options are chemical treatments, like Aquamira Drops or iodine tablets. No moving parts means there is nothing to break. They obviously are not great for turbid water full of sediment, but they are light enough that it is worth storing some in your first aid kit as a backup.

 

It’s one of the heaviest and burliest options, but the MSR Guardian Purifier is durable and one of the few filters than can withstand freezing temperatures.

 

Maintenance

The more components, the more care your filtration device will require of you. Hand pumps, hoses, bladders, and filters all require cleaning and, eventually, replacement. UV lights and chemical treatments demand far less of your time but will not be fit for every situation. With any filter, make sure it is thoroughly cleaned and maintained to ensure it doesn’t fail you at the most inopportune time.

Filter Efficacy

What’s in the water? You should have a good idea before you’re able to pick the right treatment option for your trip. In most alpine environments, bacteria and protozoa are the enemies. In developing countries or in coastal areas at the mouth of rivers, filtering for heavy metals and chemicals becomes something to consider.

It is better to be over prepared with a treatment device that can handle whatever you expect to encounter, plus some. Alternatively, consider a lightweight backup to your primary system. Shedding a few ounces only to risk drinking untreated, potentially life-threatening water is never worth it.

 

Even in alpine environments it’s worth being prepared with a water treatment device, especially if there are wildlife or other animals in the area.

 

MORE INFORMATION

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