Best Backpacking Water Filter & Purifier

Is this water safe to drink? Getting the answer to this question wrong can be disastrous on any hike or backpacking trip.

Dehydration is dangerous but drinking bad water could kill you just as easily as having no water at all. At best you could end up cutting your hike short and having to turn back.

On a thru-hike or multi-day trek it's not always practical to carry enough water so you may have to drink from rivers and streams. 

Fortunately there are some great ways to make sure that only the cleanest water passes your lips. This involves both filtering out any potential nasties as well as sterilizing, or purifying, the water that you’re planning to drink.

Most products will either filter or sterilize so for the safest water you’re going to need two separate products.

Best Backpacking Water Filter Reviews

If you hike with a hydration pack then this water filter is a great addition to your kit.

It will connect directly to your hydration pack tube and allows you to pump filtered water into it without having to remove the bladder from your pack.

The pump action is simple and allows for a really good flow rate of around 1 liter per minute. It comes with 2 quick connect hose sets as well as a bottle adaptor.

Just make sure that you store the inlet and outlet hoses separately to avoid cross contamination. While it does a great job of filtering water the connectors and moving pieces mean that there are plenty of opportunities for something to break.

If you use it carefully and store it properly then you shouldn’t have any issues. Also, avoid pumping from very dirty water or pre-filter it if you want your filter cartridge to last longer.

What We Like

  • Connects directly to hydration pack with ¼ inch drink tubes and water bottles
  • Activated carbon reduces chemicals in water and improves taste
  • Removes cysts, protozoa, bacteria, algae, sediment and spores
  • Light and compact so it won't take up valuable pack space
  • Filters water really quickly so you are not wasting time on the trail
  • Water tastes great

What We Don't Like

  • Only filters down to 0.3 micron
  • Not very durable - You need to be a little careful with connectors and handle

This water filter combines the excellent filtering that LifeStraw has become famous for with the convenience of a great hiking bottle.

The 0.2 micro first stage filter filters out bacteria and protozoa.

The second stage filter uses activated carbon to remove any odor, taste, chlorine or dissolved chemicals like pesticides that may be in the water.

The bottle has a wide mouth that allows for easy filling from a stream and a convenient mouthpiece incorporated into the lid.

Once the bottle is filled the water passes through the two filter stages and then through the mouthpiece.

Eventually the filters will need to be replaced. You’ll get around 100 liters before you need to replace the carbon filter and at least 1000 liters through it before you need to replace the first stage filter.

The first stage filter is essentially just a LifeStraw and it can be removed and used on its own.​

What We Like

  • No need for a separate filter and water bottle saving space and hassle
  • First stage filter removes 99.9999% of bacteria and 99.9% of protozoan parasites
  • Second stage activated carbon filter removes odor, chlorine, dissolved solids with zero aftertaste
  • Durable construction
  • Carabiner clip allows for easy attachment to pack

What We Don't Like

  • Leaks a little when not upright

If you’re looking for a really small and cheap water filter then it’s tough to beat the Sawyer Mini filtration system.

It’s extremely light and filters out anything bigger than 0.1 micron. The flow rate is a little slow if you’re using it to refill your hiking bottle but it flows fast enough if you’re taking a sip through it.

It comes with a drinking pouch that you can squeeze to drive the water through the filter or you could use the straw it comes with to drink directly from a water source.

It will also connect inline with your hydration pack or screw onto a standard 28mm water bottle thread.

Sawyer claim it’ll give you up to 100,000 gallons of filtered water but you do need to backflush the filter every 5 to 10 gallons to unclog the filter.

What We Like

  • Attaches inline to your hydration pack
  • Screws onto most disposable bottles (28mm thread)
  • Filters down to 0.1 micron so it'll remove even the smallest of silt particles
  • Very light and compact not taking up space in your pack
  • Filters 99.99999% of bacteria and 99.9999% of protozoa including giardia and cryptosporidium for those times when you just have to drink the dirty river water.

What We Don't Like

  • Flow is a little on the slow side for impatient people like me

Our Favorite

We really like the LifeStraw Go water filter bottle.

The convenience of having the filter built into the bottle is great.

The fact that it has both a standard filter and an activated carbon filter definitely puts it ahead of most other water filters.​

​This is my go-to water bottle for when I'm out on a day hike or traveling to parts of the world where the water is less sanitary. 

For backpacking trips it works well, but if I was setting up base camp for the family, I'd go for a larger device.​

Best for Budget​

If you’re looking to save some money then the Sawyer Mini water filter is your best bet.

You get excellent filtration in a compact and cheap water filter. The only drawback is that it’s a little slow and needs backflushing every now and again.

I'd recommend this one if you go camping occasionally and don't want to spend the extra money.

The SteriPen Adventurer is for serious hikers that want a lightweight, compact water purifier that is easy to use.

It uses UV to kill the microorganisms in the water so there’s none of the aftertaste, waiting time or allergy issues that you get from using iodine or chlorine.

You simply press the button once for 1 liter or twice for half a liter and then stir your water with the SteriPen. Once the light turns off your water is safe to drink.

It only takes around 90 seconds to purify a liter of water. The UV light kills the DNA of the microorganisms so they can’t reproduce once inside you.

This product is so effective that it’s the only water portable water treatment device to receive the Water Quality Association’s gold seal.

Because you need to stir the water it’s only practical to use with a wide mouth bottle.

What We Like

  • Compact and lightweight so very little excuse to leave it at home
  • Reusable for up to 8000 liters - that should keep even the thirstiest of us hydrated!
  • Kills 99.9% of harmful microorganisms, including Giardia, Cryptosporidium, viruses, protozoa and bacteria
  • Uses UV so there’s no aftertaste or allergies due to added chemicals
  • Water sensor can be used as a flashlight
  • No wait time - sterilizers a liter of water in 90 seconds

What We Don't Like

  • Battery operated so you have to make sure your batteries are charged
  • Has to be used with a wide mouth container

Whether you need to purify 1 liter of water for yourself or 20 liters for your hiking party this great water purifier has you covered.

It uses mixed oxidant technology to purify the water. You simply mix a brine solution made from any salt and any water and pour it into the little slot.

Once you select the volume of water you want to purify and start the reaction it uses electrolytic action to produce chlorine and other oxidants from the brine. Once the reaction is complete you pour the solution into the water and wait 30 minutes before it’s safe to drink.

There are two storage compartments in the device for salt but it’s a good idea to pack a little extra if you’re going to be out for a while.

The purifier can be charged either via the USB port or by using the built-in solar panel and a single charge is good for around 150 liters.

There are no replaceable parts and the only consumable you have is normal table salt so it’s really cheap to use.

The ability to scale between small and large quantities makes this great for a hike or even in your bugout bag.

What We Like

  • Treats anywhere between 1 to 20 liters at a time - so great if you are car camping or going backpacking with a group
  • Kills 99.9% of bacteria and viruses including Giardia and Cryptosporidium
  • Charges via USB or built-in solar panel
  • 60,000 liter lifetime with no replaceable parts
  • No pre-filtering required
  • No bad taste added to water
  • Very durable and fits into the palm of your hand

What We Don't Like

  • Takes 30 minutes to purify water
  • High price tag

If you want a simple and cheap way to disinfect water then these iodine tablets are a good option. The tablets are really simple to use.

Simply add 2 tablets for every liter of water that you need to purify, shake the bottle up and then wait for 30 minutes.

Iodine tablets are very effective at killing microorganisms in water but usually leave you with water that has a brownish color and a horrible taste.

To remove the iodine taste and color simply drop 2 of the PA Plus tablets into the treated water and after 5 minutes you’ll have purified water without the horrible taste and color.

This is not a long term water purifying solution and should rather be used as your backup plan rather than your primary water purifying solution.

Also, if you have an iodine allergy then you’ll want to skip these.

Once you open the bottle the tablets in the bottle will only be good for 12 months but they’re cheap so buy a few bottles for your hiking and emergency kit.

What We Like

  • Cheap and lightweight - easy to keep in your backpack for emergencies
  • PA plus additive removes iodine taste and color that you normally get with these tablets
  • Small bottles take up little space in pack
  • Simple to use
  • Very effective at killing viruses, bacteria and parasites

What We Don't Like

  • Only really intended for short term or emergency use
  • No good if you have an iodine allergy
  • Takes 30 minutes to work

Another simple and cheap way to purify water on the go, these chlorine dioxide tablets are a worthwhile addition to your backpack.

Killing viruses and bacteria by the simple addition of a tablet to the water, these are a good alternative to iodine. Personally I hate the taste of chlorine, but I prefer that to a dose of Giardia.

It’s as simple as popping an individually packed tablet into one liter of water, waiting for 15 minutes - or 30 minutes if you are worried about Cryptosporidium.

They won't filter silt or other suspended particles, so step away from that murky river water full of hippo-poop!​

I wouldn’t use these as my primary water sterilization method, but they make for a good backup, and are lightweight enough to keep in the bottom of your backpack.

What We Like

  • Cheap, lightweight and easy to forget about in the bottom of your pack
  • Great for emergency sterilization of water from suspect sources
  • Effective at killing viruses, parasites and bacteria
  • Doesn't taste as bad as a dose of Giardia

What We Don't Like

  • Takes 30 minutes to work
  • Won't filter the water at all, so best used with a clear water source 

Our Favorite

We love the SteriPen. It’s not a great solution for large volume water purification but for personal use on a hike it’s perfect.

I used the SteriPen on an Everest Base Camp trek and enjoyed being able to sterilize tap water in the various tea houses along the way. Certainly beats buying water in plastic bottles!

I love the no-fuss operation and the fact that there’s no 30 minute waiting time like a lot of other solutions.

I also really like the fact that this solution doesn’t involve adding any chemicals into the water.

Best for Budget

It doesn’t get much cheaper than the water purification tablets from Potable or Katadyn.

Normally we wouldn’t touch the stuff because the color and taste of iodine or chlorine treated water is just horrible.

With the PA Plus tablets added you get safe drinking water that tastes and looks (relatively) good without having to spend a lot of money.​ The Katadyn is a good alternative if you don't want to use iodine.

Portable Water Sterilizer and Filter Buying Guide

Before you can choose the best way to make your water safe it’s important to know what makes it dangerous.

In general the things you want to remove from the water are bacteria, protozoa (parasites), cysts, viruses, dissolved chemicals and particulate like sediment.

No single solution will do all of this so you’re going to need a combined approach.​

drinking stream water after purifying

Water Filter vs. Water Sterilizer for Backpacking​

A water filter will normally only remove things that are around 0.1 to 0.3 micron or larger depending on the filter. This is fine for removing bacteria, protozoa, cysts and particulate.

A filter will not remove viruses from water. Viruses are smaller than 0.1 micron and can only be killed by sterilizing with iodine, chlorine or UV light.

A good water sterilizer will kill bacteria and viruses but can’t remove dissolved chemicals from the water.​

Chemically Contaminated Water vs. Particulates​

Standard water filters use very fine microfibers to trap particulate and bacteria.

They can’t remove dissolved chemicals, odors or bad tastes from the water. To remove these you’ll need a filter that uses an absorbent medium like charcoal, also sometimes referred to as activated carbon.

A filter that uses activated carbon will absorb chemicals like pesticides, herbicides and other Volatile Organic Chemicals (VOC), heavy metals, bad tastes and odors that would otherwise pass through a standard filter.​

Water Sterilizing Methods​

Water purification is typically done by either treating the water with UV light or adding chlorine or iodine to the water.

There are pros and cons for each of these methods.​

UV Light

Works really fast and there’s no need for long waiting times after treatment. With cloudy water it may be necessary to pre-filter the water to guarantee the inactivation of all microorganisms.​

Chemical Purification​

Water sterilization tablets are either made of Iodine or Chlorine.

Iodine is very effective at purifying water but leaves you with water that really doesn’t taste great. Some people have an iodine intolerance or allergy. If you take Lithium, if you have thyroid problems or if you’re allergic to shellfish then chances are that you’re allergic to Iodine.

Adding Chlorine to water is also very effective. You don’t have as big a taste issue but in both cases it takes around 30 minutes to purify the water.​

My main issue with these is that I don't like the addition of chemicals to my water. And in order to get rid of the foul taste, you add further chemicals.

However, when given the choice between a filthy intestinal infection, or a few chemicals, I'm happy to purify my water with these tablets.

Regardless of purifying method you use, remember that they will not be able to remove dissolved chemicals from the water. They merely kill any bacteria in the water.

best water filter for backpacking

Glacial water on Everest Base Camp Trek


Some water filters only lend themselves to standalone use. If you’re planning on attaching the filter to your hydration bladder or screwing it onto your water bottle then make sure the interface allows for this.​

Flow Rate

If you’re looking for a filter that you can sip water through then the majority of them will deliver a satisfactory flow rate.

If you need to filter a lot of water at a time then make sure you get one with a decent flow rate or you’ll need to develop some patience.​

This Water would need filtering to remove the silt before sterilizing.

In Conclusion

Drinking bad water can ruin your hike far quicker than drinking no water will.

To cover all your bases it’s advised to have both the best portable water filter as well as the best portable water sterilizer in your kit. If you absolutely have to choose then go with a good two stage water filter.

You are more likely to encounter bacteria and parasites on a hike than viruses and filters are a lot easier to use when you’re on the move.

Just don’t get careless with the water outlet of the filter and make sure that the clean water side never comes into contact with suspect water.​

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