The Best Backpacking Water Filters

Nothing ruins a trip quicker than giardia. Stay healthy with these versatile filters.

Yes, you should be filtering your water—and we’ve picked out the best backpacking water filters to make it as easy as possible. While clear mountain streams can be safe to drink from unfiltered, it’s impossible to tell at a glance, and a filter can help you turn gnarly, standing water from lakes or puddles into pure, delicious H2O.

Katadyn BeFree

Katadyn BeFree Filter
Katadyn BeFree

Squeeze filters have made pesky pumps nearly obsolete when it comes to non-chemical water treatment, but they’ve had a few flaws—especially when it comes to cleaning. We’ve often arrived at a trip’s first water source only to realize our filters were clogged from the previous trip. But with the new Katadyn, all you have to do is swish it in water, clean or dirty, and you’re clear.

It’s also fast. A two-handed grip blasts out water at 1 liter per minute—comparable to pump filters but without the workout. “The water squirts out as fast as you can suck,” Lyons said. The BeFree condenses the hollow-fiber filter into a low-bulk package that fits in the neck of a soft-sided bottle. We used it in Colombia and found it so quick and handy that the group-size gravity filter we brought stayed in its bag, while everyone opted to use their BeFree. Between the bottle’s inch-wide opening and its pliable sides, it’s easy to dip and scoop from lakes and other non-flowing water.

We did spring one leak after jamming the soft bottle in our pack on our climb up Colorado’s Longs Peak, but a dab of Seam Grip fixed it permanently.

Squeeze filters with pump-like reliability? Fill’er up.

$45; 2 oz; Buy Katadyn BeFree Now

MSR TrailShot

MSR TrailShot Filtration
MSR TrailShot

Straw-style filter designs come with one big problem: They aren’t much good if the water is farther away than the straw is long. This smaller-than-a-Clif-Bar water filter solves that with a 15-inch intake hose that’ll thread into tight places. In lieu of a handle, the TrailShot uses a silicone squeeze pump (think: blood-pressure bulb) to draw water up through the hose and hollow-fiber filter element. It clogged fast when we drank silty water straight off a glacier in Peru, but a few swishes cleaned it. Output-wise, it does about a liter a minute. Caveat: There is no carbon, so it doesn’t do much to improve the taste of water from less-than-desirable sources.

“For multiday backpacking trips with regular access to water, I leave the water bottle at home and just bring my TrailShot,” says a thru-hiker.

$50; 5 oz; Buy MSR TrailShot Now

Grayl Ultralight

Grayl Ultralight Filter
Grayl Ultralight

This all-in-one Grayl filter catches bugs, off flavors, and everything else, leaving behind a cup full of the best-tasting water we had all year.

The system works kind of like a French press coffee filter. Fill the larger container to the line with dirty water, place the smaller container inside, and lean into it for about 15 seconds. Testers noted the watertight lid (which prevents cross contamination) has to be slightly ajar, or else it’s impossible to press down the filter. Ding: The heels of our hands got sore from pushing against the plastic rim.

The inner container holds just 16 ounces. It takes multiple fill-and-press cycles to top up Nalgenes or reservoirs, making this most appropriate for trips in places with lots of water where you can fill, press, cap, and move on.

The three-tier filter is made from electroadsorptive media (a positively charged mesh that traps protozoa, bacteria, viruses, and chemicals), plus carbon for removing taste and heavy metals, and silver to keep the filter clean. “I drank water in Nepal out of this bottle for a month and never got sick,” said a pro snowboarder after a trek to Annapurna Base Camp. Drawback: The filter has to be replaced every 150 or so liters and new inserts cost $25.

The food-grade plastic is totally bombproof. “I dropped mine square on a rock when it was full and was expecting the worst,” says one Colorado tester, “but the bottle only took a superficial scratch.”

$60; 11 oz; Buy Grayl Ultralight Now

LifeStraw Universal

gear guide 2018 lifestraw bottle filter
LifeStraw Universal

It doesn’t get any easier than filling your bottle straight from the source and just drinking. But until now, fans of LifeStraw’s hollow-fiber filter could only use it in a LifeStraw bottle (sold together). The Universal gives you a choice, letting you pop the two-stage filter into most brands of hard-sided bottles. The filter eliminates bacteria and protozoa and reduces organic chemicals, and improves taste. Downside: You gotta suck pretty hard to drink, like slurping up soft-serve ice cream with a straw.

“New Zealand’s Whanganui River was swollen with silty rainwater during our three-day paddling trip,” one tester says. “But I dipped my bottle, sucked through the LifeStraw, and am happy to report the water was grit-free and tasted fine.”

$35; 3.7 oz; Buy LifeStraw Universal Now

MSR Trail Base Water Filter Kit

gear guide 2018 MSR water filter kit
MSR Trail Base Water Filter Kit

This kit is the closest we’ve seen to an all-in-one water system. The Trail Base can be used to drink from the source, filter for a group, or carry water. It includes a pocket-size TrailShot filter (with a quick-connect head, not just a drinking spout) and a pair of 2-liter Dromedary Bags. “Pumping the bag full takes forever, but integrating the TrailShot and using the system as a gravity filter let me treat 2 liters in just over 2 minutes,” says one tester who used the Trail Base in Oregon’s Eagle Cap Wilderness. Ding: The Trail Base’s price is a bit more than the sum
of its parts.

“In Oregon, we met people who had forgotten their filter,” our tester says. “We provided water for nine instead of two that night, with minimal trips back to the stream.”

$140; 1 lb, 6 oz; Buy MSR Trail Base Water Filter Kit Now