For most people, water treatment is a must-have on backpacking trips. Heck, even a long day of hiking can require a filter, if you don't want to carry liters of water. It can also sometimes be a good idea to treat water while traveling, or even in the course of daily life at home.
Before the comments section implodes, we’d like to include the caveat that this article covers the filters we were sent to test. We reached out to several brands that did not respond to our inquiries, including MSR, LifeStraw, Steripen and Katadyn.
We are aware these filters are out there and have used them, but they are not included here because we didn’t test them. We’d like to note that the Katadyn BeFree is a popular alternative to the ubiquitous Sawyer Squeeze, with a fast flow rate, low weight, and super flexible bag.
Hikers can also use purifying treatments like Aquamira drops, iodine, or even bleach (repackaged into an eye dropper).
Here are the water filters tested for this article, with info on how they work and who they might be best for.
Best For: Backpackers who like a variety of uses for a small filter, or who typically use a hydration bladder in their pack
The HydroBlu Versa Flow looks similar to the Sawyer, and has the ability to use the same “squeeze” filtering technique. It also features hollow fiber technology. This is a dual-threaded filter with a variety of uses—it can be used inline (which includes cutting your reservoir hose in two pieces), as a squeeze filter, or as a straw filter.
I found this filter easy to use with a fast flow rate, and it weighs just a few ounces. It reminds me of the Sawyer, but I haven’t used it long enough to compare flow rates and durability. It’s lightweight and compact, and it fits easily into the hose on my bladder for extended rides on my gravel bike.
Like the Sawyer Mini with the dual threading, it is compatible with standard threading on water bottles and water pouches. This filter is advertised as inline, so I’d recommend it for hikers who primarily use bladders in their packs. It would also be great for trail runners or bike packers who don’t want to take the time to filter water, instead filling up several liters of a reservoir at once and then drinking on the go.
Best For: The Original Sawyer Squeeze is most often used by weight-conscious backpackers and thru-hikers, screwed into water bottles or used with a soft-sided bladder/ pouch
The Sawyer line can be used in taps, for backpacking, and inline. Sawyer filters use a hollow fiber membrane similar to others on this list. Unfiltered water is pushed into the core of the filter through tiny “micro pores.” These pores are tiny enough that bacteria can’t fit through… forget dirt or silt. The filter action is simple—screw the filter onto the pouch or water bottle, squeeze the unfiltered water through the filter, and clean water comes out on the other side.
You do need to clean (backflush) these filters, because as they get used, the pressure needed to push the water through will increase as it feels “clogged.”
This is the filter I’ve used the most, and I have some that have lasted thousands of miles. They are simple, reliable, and the customer service at Sawyer can’t be beat.
Alternatives to the Original include the Sawyer Mini ($25) and the Sawyer Micro ($29). While both of these filters save about an ounce and a little bulk, they do tend to slow down faster than the Original, and the price difference is negligible when you think about how long these last and how much water you’ll be filtering.
Best For: Base camp adventures, large groups, long lunch breaks
I’ve used gravity filters on media trips and base-camp trips (where we take off on day trips from one location) and it’s nice to be able to set it and forget it, especially for a large group.
If you’re stopping by a water source and plan to stay for a while, plus you need to filter large amounts of water, hanging a few gravity filters from nearby tree branches can be a real time and effort saver.
Gravity filters work by filling a “dirty” bag with unfiltered water, and can be connected to a “clean” reservoir via hoses and an inline filter. If the package doesn’t have two reservoirs, you’ll fill your own bottles.
The Sawyer Gravity Filter System comes with a one-gallon reservoir, a hose, and a dual-thread Mini. You’ll fill your own bottles or the second reservoir from there, simply by hanging the bag of water with the Mini below, and then letting gravity do the work.
In less than 10 minutes (with zero effort!) a large quantity of water can be filtered.
Platypus and MSR also make durable, reliable gravity filters.
Best For: Backpackers looking to try an alternative to the Katadyn BeFree or the Sawyer Squeeze, from a company known for extremely durable reservoirs
This is the newest filter on the list, and the latest offering from Platypus. Platypus has primarily focused on gravity filters until now, and if this filter holds up for the season, it could be a strong competitor to the Sawyer Squeeze.
This whole system weighs just 3.3 ounces, comparable in size and compactness to the Original Sawyer Squeeze. The threading is the same as the others on this list, compatible with Platypus reservoirs and most standard water bottles like SmartWater.
It has a “shake to clean” system that is simple and doesn’t require additional gadgets or gear, making the whole system highly streamlined. So far I’ve noticed a very fast flow rate, but then again, I haven’t used it for a super extended trip or a full season.
One thing I’ve always loved about Platypus is their durable bladders and reservoirs—while other pouches seem to burst or break at the seams, Platypus can handle longer water carries and pressure filtering.
You have a few options with this: the QuickDraw System comes with a bladder, but the QuickDraw can be purchased on its own for $30.
Best For: Travelers and day hikers who want clean water almost instantly
As someone used to purifying tablets or simple squeeze-type filters, this GeoPress looked confounding to me. I’m a fairly lightweight backpacker, so this type of bottle isn’t something I would normally carry. When I travel, I bring purifying drops.
But this bottle is its own filter, and in less than 10 seconds, it purifies water with almost no effort on the user’s end. The technology is a mouthful, and includes things like “electroadsorptive media,” which Grayl says “captures pathogens and inorganic contaminants like a magnet.” Well then!
Luckily, using the filter is easier than pronouncing the technology that makes it work. It’s sort of like a French press. Just fill the outer container with the unfiltered water, then press the plunger into the outer container. The plunger has a filter at one end, and the water pushes through the filter into the inner bottle. Dirty water never touches the inner bottle, and it takes just a few seconds. You can then drink right from the bottle.
Now that I have this, it’s something I’ll certainly take with me traveling. It’s bulky but not super heavy, and if I’m going to be carrying a reusable bottle anyway, why not carry one that has the capacity to filter its own water?
Best For: Travelers, in-town use, people who want to purify water at homes or on trips
Like the Grayl, you won’t be using this for ultralight backpacking, and it’s the most “in-town” type of filter on this list. I could see taking this with me to the gym, on work trips where I don’t like the taste of city water, or to somewhere where treating your water is recommended — which conveniently also eliminates the need to buy disposable water bottles.
I love the emphasis on sustainability, and it makes perfect sense for people living in a place where they might not want to drink the local water, and don’t have a tap filter like the Sawyer listed above.
This bottle itself is double-walled to keep water cold, and it’s also self-cleaning (yay for no mildew smell!).
The treatment is super easy to use—it uses UV light like the Steripen, and a simple press of the cap will activate the technology. Just fill the bottle, tap the top, and let it work its magic.
Since the water isn’t getting pushed through a filter, you will want to make sure the water doesn’t have debris floating around. Also, like the Steripen, you will have to make sure your Crazycap is charged, but the package comes with a charger and instructions.
Again, this Crazycap isn’t necessarily for backcountry use, rather it wants to help eliminate plastic / single-use water bottles for people in towns or places where they’re apt to buy disposable bottles to avoid drinking the city water.
MSRP: $24.95, filter only; $44.95, filter + 1.0L Hydrapak collapsible flask
Best For: Weekend warriors and shorter backpacking trips
While we didn’t officially review the Katadyn BeFree (we sent them many an email for samples), we do have several staff members here at GGG who use it as their go-to filter. Ultralight in weight, the Katadyn BeFree has lightening fast filtration. Downside? Longevity.
Maggie Slepian is a full-time freelance writer based in Bozeman, Montana. She is the co-founder of BackpackingRoutes.com, and spends as much time outdoors as possible. You can follow her here, or find clips and contact info at Maggieslepian.com