Need help getting started? Read our four-part guide to backcountry water treatment:
Part 1: Proper Hydration
Part 2: Keeping Your Water Supply Safe
Part 3: What’s in Backcountry Water?
Part 4: Methods for Making Water Safe
The best water purifiers, reviewed and curated by the Trailspace community. The latest review was added on March 10, 2022. Stores' prices and availability are updated daily.
In order to show you the most useful information, we have omitted some products.
Recent Water Purifier Reviews
Avoid this company The first SteriPen I got, I never got to use. I tried it at home a couple of times for a couple minutes. Packed it away for 6 months. Pulled it out when I need to actually use it and it never turned on. Charged it, etc... it just stopped working. I think this company is no longer around because when I looked, I couldn't find any contact information. If it is, they rose from the grave. Stay away. Great idea, but a product you can in no way count on. Full review
It works really well. Trusted my health with it on third world travel. I traveled all over India from Sri Lanka in the south to the Himalayas in the north with a 32oz Nalgene bottle and my SteriPen Adventurer Opti. Trusted this product fully with sterilizing my water. If I hadn't used the pen, I would have been sick as a dog like some of my traveling companions who risked it all and didn't heed my warning. Just swish it around in the water for a minute or two while the UV light kills proto and giardia. Full review
The GeoPress is fast and clean, never leaks, and does a better job of providing super clear water than my Lifestraw did. You do have to use a fair amount of pressure to push it down, but the excellent results are worth it. Oh, and it is also easier to clean with a quick rinse. Use this just like a water bottle—plunge and you are good to go. I have filtered lots of river and pond water with excellent results. No muss, no fuss. If you are just filtering municipal water, get a cheaper, lighter… Full review
Lightweight and easy to use water filtration system. I have had my Adventurer for more than 10 years. It works using a UV light. I was skeptical about this, but my dad used to design sewage treatment plants and said "oh yeah, that will do it." The Steripen itself is very compact—about 2 inches wide and about 8 inches long. I have even stuffed it in a purse when flying across the country. This was a huge benefit over the Katadyn Hiker pump I had been using previously in both weight (SteriPen… Full review
I bought this product years ago, when it was newly on the market. There are too many "Caution Statements" not fully covered in the instructions. All of this may have been addressed since then... Perhaps not. (From ORIGINAL Instruction Booklet)Notice in the instruction book's photo, there are NO DROPLETS on the glass, above the water line… Because they will NOT be cleaned. Cautions—not fully explained! These are not listed or explained in the instruction booklet! When you dip your Nalgene bottle… Full review
2.6 ounces, no pumping, nothing to clog, 90 seconds treated water I have a Steripen Adventurer that I've used off and on for several years. It's never given me any trouble, but utilizes CR123 batteries, while my headlamps use AAA. It's pretty light, but not crazy light. The Steripen Ultralight weighs under 3 oz (2.6 oz) and is very compact. It utilizes a rechargeable battery (via a USB Micro). I purchased one a couple of months ago and took it on a short (3 days/2 nights) backpacking trip. It… Full review
The MSR Guardian Gravity Purifier is an all-in-one water treatment system that is ideal for groups, or people needing potable water in larger volumes. Not only removing bacteria, protozoa, sediment and particulate, MSR’s new flagship purifier also removes the tiniest viruses, while also using activated charcoal to improve flavor and reduce chemicals. The Guardian’s new purge valve quickly and easily cleans the filter to maximize flow rate, removing debris. Mountain Safety Research (MSR) is no… Full review
The Grayl UL is heavier and more expensive than in-line filters like the Sawyer Mini or Squeeze. But when we consider that it doesn’t require a container and also filters out viruses and chemicals/odors, it shows some advantages. It’s an all-in-one solution, good for outdoor use, but perhaps even more for emergencies: for those qualities I keep one new in my bug-out-bag. I see the Grayl UL as more of an all-in-one solution to water treatment and storage than a simple filtration system. I can… Full review
For day hikers and overnight adventurers, fill this beauty up with water at the start of your hike and when you find a water source, drink what you have and refill the Grayl. Original reviews talked about how difficult it is to press (filter) the water, think of a french press coffee maker, not hard at all and I am quite small. I love this simple, perfect system This is an easy to use, effective, fast source of filtered water. The capacity of fresh water that is also stored directly in the french-press… Full review