What is the best water filter for backpacking?

What is the best water filter for backpacking?

One of the most important pieces of gear in any backpacker’s pack is their water treatment system.  You should assume any water source is potentially contaminated and filter it before consuming, cleaning foods, cleaning pots, or using it for brushing your teeth.



I’ve read about many backpacker’s who do not treat their water, especially when traveling to remote mountain ranges, but I wouldn’t risk it.  That crystal clear mountain stream may seem pristine to the naked eye but there are most likely millions of microorganisms thriving in it.  You are likely drinking human or animal feces and can catch Ecoli, Salmonila, Giardia, Cryptosporidium, or Toxoplasma Gondi to name just a few.  Its not only feces, but dead animals as well.  You never know what might lay upstream and if you’re not taking precautions to purify your water, you will be asking for trouble.


Its a good idea to have a main water treatment system and then also a backup, just in case the main one gets lost, broken, or malfunctions.   I like to take a filter and then some emergency water purification tablets or Aquamira Drops as my backup because they are really lightweight.  So, what is the best water filter for backpacking?  Let’s first look at some of the qualities needed to make a filter great.

Qualities of a good backpacking filter

  • Filter micron size of 0.2 or less – The microscopic openings in the filter are measured in microns.  Bacteria range in size between 0.2 and 1 microns and they exist almost everywhere on earth.  Viruses are about 100 times smaller than bacteria and range in size between 0.004 and 0.1.  Viruses are typically difficult to remove with a backpacking filter but they are usually not much of a concern if you will be backpacking in the United States.  If you are travelling internationally or want to be sure to get rid of any viruses, look into getting a water purifier rather than just a filter.  Purifiers protect against all three classes of microbes, bacteria, viruses, and protozoa.  Viruses can also be removed by boiling, UV light, or chemical treatment.  Cysts are protective sacs made by protozoans and some bacteria and are similar to spores.  They are usually between 2 and 50 microns in diameter.
  • Water Flow of at least 1 L/minute – The speed that water flows through the filter is an important factor especially if you are travelling where water is scarce and you need to fill up all your bottles and bladders.  You don’t want to be wasting too much time in the field filtering.  Most backpacking filters can filter 1 Liter of water in about a minute, so look for that or better.  Some can do it as quickly as 40 seconds!  There are some immediate water filters such as the Lifestraw and Sawyer Mini where you can drink immediately from a water source or water bottle but the water flow rate is often fairly slow.
  • Lightweight – We all know that the lighter your pack, the more enjoyable your hike will be.  Be sure to look for a filter that weighs as little as possible.  One way to cut out a couple ounces is to ditch the carrying case/bag.  Every filter will end up weighing a little more once you use it because small amounts of water become trapped inside.  You should try to let your filter dry out overnight.  If you will be hiking in cold/freezing temps, be sure to bring your filter in the tent with you at night.
  • Compact – While this might not be a concern for some people, I prefer a smaller water filter because added bulk makes it difficult to keep my backpack a reasonable size.  There’s only so much room in a backpack so its best to take the size of your filter into consideration.
  •  Easy to use and clean – This is a subjective matter, but you will want a filter that has few parts and is simple to use out in the field.  You will be filtering water at all times of day – early morning, while covering miles, and when your exhausted at the end of the day – and the last thing you will want to do is be fiddling around with a tricky water filter.  Gravity filters are an easy option because you simply fill up the reservoir, attach it to yours, and let it do its magic.  Filters need to be backflushed to keep them clean and you don’t want one that needs too much maintenance.

Water Filter Comparison

ProductFilter TypeFilter MediumWater Flow RateWeightSizeEase of UsePrice
Katadyn Hiker Pro Microfilter
Katadyn Hiker Pro Microfilter
Pump 0.2 Micron glass fiber/carbon core/filter protector1 L per minute11 oz6.5 x 3 x 2.5 inGood$75.98 on Amazon
EXMSR Miniworks
MSR Miniworks
Pump0.2 Micron ceramic with carbon core1 L per minute14.6 oz7.8 x 3.8 inFair$89.95 on Amazon
MSR Sweetwater
MSR Sweetwater Microfilter
Pump0.2 Micron silica depth matrix with carbon 1 or more L per minute11 oz7.5 x 2 inGood$79.98 on Amazon
MSR Guardian Purifier
MSR Guardian Purifier
Pump0.02 Micron advanced hollow fibers2.5 L per minute1 lb 1.3 oz8.2 x 4.7 x 3.5 inGreat$349.95 on Amazon
Platypus gravityworks
Platypus Gravityworks 4 L Filter System
Gravity0.2 Micron hollow fiber1.75 L per minute11.5 oz2 x 8,5 in (filter)
17.7 x 9.1 (reservoirs)
Excellent$119.95 on Amazon
Sawyer 4 L Water Filtration
Sawyer 4 L Water Filtration System
Gravity0.1 Micron hollow fiber membrane1.3 L per minute18 oz20 x 10 inGreat$146.95 on Amazon
MSR Autoflow gravity filter
MSR Autoflow Gravity Filter
Gravity0.2 Micron hollow fiber1.75 L per minute11.1 oz11.3 x 20 inExcellent$119.95 on Amazon
Katadyn Gravity Camp 6 L
Katadyn Gravity Camp 6 L
Gravity0.2 Micron pleated glass fiber/carbon core/filter protector2 L per minute12.4 oz4 x 6 in (filter)
48 in (hose)
Great$85.47 on Amazon
Sawyer SqueezeSawyer Squeeze
Read the Review
Squeeze0.1 Micron hollow fiber membrane1.7 L per minute3 oz5 x 2 in (filter)
11 x 6 (squeeze pouch)
Excellent$44.54 on Amazon
Sawyer Mini
Sawyer Mini
Squeeze or Straw0.1 Micron hollow fiber membrane1.7 L per minute2 oz1 x 5 inGreat$19.99 on Amazon
MSR Trailshot
MSR Trailshot

Read the Review
Squeeze0.2 Micron advanced hollow fibers1 L per minute5.2 oz6 x 2.4 inGood$49.95 on Amazon
Straw0.2 Micron hollow fiber membraneNot Applicable2 oz1.2 x 8.8 inGood$19.95 on Amazon
Grayl Water Bottle
Press, Water bottleElectro absorption and activated carbon, removes 99.9999% of all viruses and bacteria and 99.999% of all protozoan cysts16 fl oz per 15 seconds or 2 L per minute 10.9 oz9.5 x 2.7 x 2.7 inExcellent$59.50 on Amazon
Katadyn BeFree
Katadyn BeFree
Water bottle0.1 Micron hollow fiber 2 L per minute2.3 oz11.3 x 3.5 x 2.8 inGreat$39.95 on Amazon

There are lots of options for water treatment on the trail.  These include pump filters, gravity filters, squeeze filters, straw filters, water bottle filters, chemical treatment, and UV light.  For this article, I want to discuss the various filters only.

Pump filters are the most commonly used type of filter among backpackers.  With these, you place a tube from the filter into your water source and then manually pump the water into a bottle or container.  This requires a little labor but can filter large volumes of water for groups of people.

Recommended pump filters 

  • Katadyn Hiker Pro
  • Katadyn Vario
  • MSR Miniworks
  • MSR Sweetwater Microfilter
  • MSR Guardian Purifier

Gravity filters can be really convenient for filtering large amounts of water for groups of people.  They usually come with 2 Liter to 6 Liter bags and can filter these large amounts of water rather quickly.  I would use a gravity filter for a group trip that involves staying at a base camp near water for multiple days.  That way you will have easy access to water when its needed for cooking or washing.  These filters require less effort than pump style since you just hang the dirty water bag and let it run down through a filter and tube and into a clean water bag.

Recommended gravity filters

  • Platypus Gravityworks 4L Filter System
  • Sawyer 4L Water Filtration System
  • MSR Autoflow Gravity Filter
  • Katadyn Gravity Camp 6L

Squeeze filters involve squeezing water through a filter and into your clean water bottle.  There are only a couple of these on the market and they are the Sawyer Squeeze and the MSR TrailShot.  This type of filter is not ideal for large groups of people but they work great if you’re hiking solo, trail running, or maybe with just one other person.  For the Sawyer, you attach a dirty water bag to the filter and then squeeze and roll the bag, pushing water through the filter and into a clean bottle.  With the MSR TrailShot, you place a tube from the filter into your water source and then squeeze/pump the filter with your hand which pushes the water through the filter and out into your clean bottle.

Recommended squeeze filters

Straw filters are typically used by ultralight backpackers and hikers or trail runners who do solo trips.  They are great for areas where water is plentiful because you can drink directly from the water source.  The Lifestraw was originally invented for natural disaster relief efforts overseas and is used by millions of people worldwide.  Straw filters do have a maximum capacity for the amount of water they can filter so you will have to keep buying new straws.

Recommended straw filters

  • Lifestraw

Water bottle filters are similar to straw filters in that they are best for hikers and trail runners.  These will be for individual use and are best in areas where water is plentiful because you will need to keep filling up your bottle.  Most backpackers who use these are ultralight backpackers and are looking to minimize weight in every possible area.  There are not a whole lot of options for a decent water bottle filter.

Recommended water bottle filters

  • Grayl Water Bottle
  • Katadyn BeFree

Best Overall Water Filter

Platypus Gravityworks 4L Filter System

$119.95 on Amazon



This gravity fed filter also comes in a 2 Liter version.  It has a very fast flow rate and can filter 4 liters of water in 2.5 minutes!  It has a hollow fiber filter and removes bacteria and protozoa down to 0.2 microns.  Its easy to use, requires little maintenance, and is fairly lightweight.  The Gravityworks has the ability to clean and store 8 liters of water but you can filter as little or much as you want at a time.  You can also store your water in the reservoir bags so you can have clean water on hand or transport it when needed.  This is a water filter, not purifier, so it does not eliminate viruses, which are more of a concern with international travel.  If you are looking to travel abroad, I suggest the MSR Guardian Purifier.  The absence of moving parts make this a reliable filter that is not likely to malfunction or break.  To backflush or clean this unit, you simply flip the unit over and let water flow through the opposite direction.


Best for solo backpacking

Sawyer Squeeze

$44.54 on Amazon


The Sawyer Squeeze shines in ease of use and affordability.  It weighs in at only 3 ounces and costs around $45!  This is my preferred method of water treatment.  Its flow rate is rather quick and I can filter a liter of water in about 30 seconds.  It is a hollow fiber filter and removes bacteria and protozoa down to the 0.2 microns.  The Sawyer does not filter out viruses but they are more of a concern for overseas travel.  It comes with three mylar foil bags of varying sizes which are BPA free.  Also included is a syringe for the simple process of backflushing.  You have the option of attaching the filter to your water bottle and drinking directly from the pop up drinking spout.  I like that there are different accessories for the Sawyer Squeeze such as an adapter for hydration packs and a cleaning coupling.


Best for international backpacking or hiking

MSR Guardian Purifier

$349.95 on Amazon


While not the lightest weight or most affordable, this is a true water purifier and can safely be used for international travel or backpacking.  The Guardian can purify a liter of water in about 45 seconds.  One of my favorite features with this unit is that it is self cleaning and requires no maintenance!  Backflushing is not required because with every pump you make, it does this for you.  There is a separate outlet hose for the backflushed water to escape the unit.  This pump is durable and has been freeze tested.  Most filters become ineffective when left out to freeze but the Guardian can handle it.  It also has a huge filtering lifespan at 10,000 liters.  This purifier is overkill for most North American travel, but if you want to be protected overseas, the Guardian is a great investment.

Best for trail running or fast packing

Katadyn BeFree 

$39.99 on Amazon


The BeFree is marketed to trail runners as a collapsible flask and can be rolled up and stuffed just about anywhere.  It holds 0.6 liters of water and filters out bacteria and protozoa down to the 0.1 micron.  The filter is fairly easy to clean and no backflushing is required.  Simply shake or swish the filter out.  This unit does only have a filter lifespan of about 1000 liters and this depends on the water quality.  It has a tested water flow rate of about a liter per minute.


Best Value for the Money

Sawyer Mini

$19.99 on Amazon



The Sawyer Mini is the little brother to the regular sized Sawyer Squeeze and is just as effective but only $19.99!  The main difference between the two is that since the Mini is more compact there have been reports that it easily clogs and needs to be backflushed very often.  You will probably need to bring the backflushing syringe with you on even short trips where you might be able to do without if for the regular Sawyer.  This tiny filter by itself weighs only 1.4 ounces.  The Mini has a hollow fiber membrane inline filter that removes bacteria and protozoa down to the 0.1 micron.  It is rated for a lifespan of 100,000 liters which is huge.  This is one of the most versatile filters on the market.  Included is a drinking straw so you can use it as you would a straw filter and drink directly from the source.  You can also squeeze one of the mylar foil bags into a clean water bottle, screw onto a disposable water bottle or bag and drink directly from it, or attach it to a hydration bladder with no additional pieces or adapters.


So, what is the best water filter for backpacking?  That depends on what your priorities are and what size group you will be hiking with.  Some backpackers will go with the lightest option, others with the cheapest, or others with the most effective.

What’s your choice for water treatment on the trail?  Leave a comment below and let me know if you have any additional questions or concerns!

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6 thoughts on “What is the best water filter for backpacking?”

  • Wow. Who knew there was such a choice available. For me I would pick the most lightweight option, although they all seem pretty compact. Thank you for posting such an in-depth article on the filters as well, as one never knows how often to change them, clean them etc.
    Living in Mexico and hiking a lot, I will now definitely think about purchasing one of these.

    • Weight is always a key factor for me as well.  If you’re hiking where there are viruses present, I suggest investing in a purification system, such as the MSR Guardian, rather than just a filter.  

  • I never realized there were so many options for water purification in the field!

    The Lifestraw has worked well for me on short day trips. But, for overnight or several day trips, I think the Katadyn Gravity Camp 6L would be ideal!

    But, I like the pump options, too.

    Have you had any experience with the Berkey line of filters? I was curious as to how effective they might be, especially, their Berkey Sport Bottle. Have you used it?

    I really liked your article! I can see you really know your water filtering and, you are absolutely correct when you say do not trust any water source. Filter everything! I have experienced my share of stomach cramps and dysentery from neglecting to filter what I thought was “pure mountain spring water.”


    • And this article is just focused on filters alone!  There are other methods as well like UV light and chemical treatment as well which I am hoping to get around to writing about soon.  

      I have heard of Berkey Filters but thought they were focused more on larger, in home filters for daily use.  I haven’t used the Berkey Sport Bottle but it looks like it filters down to the 0.2 micron so it would be sufficient for backpacking use.  Or at least for day use since it only holds 22 oz.

  • Katie,
    Wow, wonderful site. It has been awhile since that last time I went backpacking but you have revived my interest. I still walk a lot, 7-8 miles a day but not on the trail.
    Your review of water filters and purifiers is very thorough, there’s so many to choose from.
    What is your pick for the best pump filter?

    • Wow you would do great on the trail if you are hitting 7-8 miles a day!  Go for it!  

      I would say my top pick for best pump filter is the MSR Sweetwater.  Its really light, compact, and you get a high output of water for the amount of effort needed to pump.    

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