Best water filters and purifiers for hiking in 2025: Our top picks for making wild water safe

When it comes to staying hydrated on the hill, there are options beyond water bottles. With a water filter or purifier, you can make wild water drinkable, which allows you to top up on the go and carry less liquid to start with.

Negating the need to carry litres of water with you on a trek is a reasonably compelling case in itself, but the world of portable filters and purifiers for hiking and outdoor use is as murky as the water they allegedly cleanse. This is primarily because there are no mandatory regulations for this market. There are voluntary standards, which we look at further down this guide, but even these aren’t perfect.

How we tested the best hiking water filters and purifiers

Our teams at Live For The Outdoors and Trail magazine getting off-grid and exploring remote areas, along way from shops or refill stations. We hike and backpack through some of the most exciting mountain terrain in the world, and we don't always want to be laden down by energy-sapping litres of water.

So we often carry water purification systems in our packs, particularly on wild camps, so we can make wild water safe to drink. The suggestions below have been tried and tested by a number of our team members, including Ben Weeks, Oli Reed, Tom Bailey, Matt Jones and Chris Williams. Everyone has their own personal preference for the best system, so we've tried to make our recommendations as varioed as possible. For more info on how we test out kit, click here.

The best hiking water filters and purifiers reviewed:

As a very useful accessory for hikes, we've compiled a guide to help you understand what to look for in water filters and purifiers at the bottom of this article. First, here are our reviews and recommendations for the best models out there.

Water filter and purifier standards

Because the water filter and purifier market is unregulated, it's very easy for products to be all mouth and no substance.

However, some voluntary standards have been set by NSF. The ones to look for are NSF Protocol P231 and NSF Protocol 248. These standards test devices thoroughly for the removal of waterborne pathogens, which is what you want for wild water sources.

This sounds ideal, but there's a hiccup with NSF P231. Testing includes with tap water and water with increased levels of organic matter, dangerous microorganisms and turbidity (more murky) to simulate contaminated wild water. Products don't necessarily have to be subject to the wilderness water and therefore aren't subject to as thorough testing as other products might.

The best way to get a completely clear answer on how a filter or purifier has been tested, is to contact the manufacturer.

Contaminated water

The risk of contaminated water can occur anywhere, but increases in certain areas or scenarios. The three types of pathogenic microorganisms filters and purifiers help remove from water are:

- Protozoa: Single-cell organisms that form cysts, and are common in unfiltered water sources. 
- Bacteria: Single-cell organisms, but smaller than protozoa that thrive in warmer water. 
- Viruses: Parasites that are even smaller than bacteria that propagate in living cells.

The safest places to source wild water from are at higher elevations, above the vegetation line. Here, you are closer to the water source and the risk of contamination is lowest.

Below the vegetation line you encounter farmland, and more wildlife, which increases the level of water contamination (particulates, protozoa, and bacteria). Inside built-up habitation zones are where the risks of unsafe drinking water are highest, especially in developing countries.

What to look for in water filters and purifiers for hiking

Filter vs purifier: Before making any decisions, this is the most important piece of information you need to know. A water filter will remove cysts and bacteria from water. A water purifier will remove viruses as well.

Sterilising and filtering: Some treatments will sterilise water but won’t remove impurities. Tablets can remove bacteria, cysts, and viruses but not particulates, for example. Some filters will deal with bacteria and particulates but not viruses. But there are some purifiers that deal with bacteria, particulates, and viruses, and even other contaminants like heavy metals. Know what water dangers you’re likely to face and choose the most appropriate treatment for those risks.

Weight and bulk: Most water purification options are relatively compact and lightweight, but some are more so than others. It all depends how much water you’re likely to need to purify. A big, heavy filter that takes up as much space in your pack as a large bottle of water may be of limited value on a short day-hike.

Volume of water: Do you only need something that will purify a small amount of water at a time, allowing you to top up your bottle or bladder, or will you need to treat greater quantities of water for multiple drinkers? Some devices are designed specifically for higher volumes, while others are intended for individual use.

Taste: Some chemical treatments, such as chlorine tablets, can give the water an unpleasant taste, making it much less palatable, albeit safe to drink. Chlorine dioxide is much better.

Water storage: Do you need a device that cleans and stores water, or will you be carrying a separate water bottle or bladder into which clean water can be transferred?

About the author

Ben Weeks is Trail magazine's long-serving gear editor, and one of the most respected testers of outdoor kit in Britain. Plus, he loves a remote wild camping adventure, so what he doesn't know about water filters isn't worth knowing.

Don't forget to subscribe to the Live For The Outdoors newsletter to get expert advice and outdoor inspiration delivered to your inbox!