Best Survival Water Filters | Tested & Proven

Being able to filter water can save your life. Just ask anyone in a developing country where the popularity of portable and personal water filters has skyrocketed. When you are faced with survival, you want a proven filter that won’t let you down. The best survival water filters will do just that in a compact package without any assistance from electricity or other power sources. There are a slew of brands and types to choose from when it comes to water filters that will actually hold up in a survival situation.

I’ve been testing survival water filters for several years now, starting in 2016. For this review, I’ve measured, taste-tested the filtered water, and even cut apart the filters to find the best.

My top recommendation is for the Waterdrop Gravity, which packs a lot of versatility in a compact kit at a respectable value.

If you want something even smaller, I suggest the Sawyer Mini, which can filter a huge amount of water for its size with proper maintenance. I also suggest a battery-powered reverse osmosis filter and a fast-filtering water bottle as niche solutions.

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Contents (Jump to a Section)

• Best Survival Water Filter
• Best Straw Filter
• Best Reverse Osmosis Filter
• Best Water Filter Bottle
• Comparison Table
• How I Tested
• Why Trust TruePrepper
• Analysis & Test Results
  • Value: Cost vs. Benefit
  • Filter Effectiveness
  • Flow Rate
  • Durability
  • Versatility
• How to Use a Survival Water Filter
• Who Needs a Water Filter?
• Sources & References
• Conclusion

Our latest update of the best survival water filters includes more pictures, pros vs cons, and adjusted prices. When you buy through our links, we may earn a commission. Disclosure»

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Also available to buy at Waterdrop and Walmart.

Gravity filters are all over the place, and for good reason. They are versatile and do all the water flow work for you with gravity. The Waterdrop Gravity water filter has been cost-engineered, making it exceptionally affordable for the life-saving functionality you get. It has a small 1.5-gallon capacity bag, and the filter has a respectable 5,300-liter lifespan. The flow rate isn’t going to hold you back compared to the bag capacity.

Specifications

• Filtration Type: Hollow fiber and carbon, 0.1 micron
• Filter Capacity: 1,400 gal (5,300L)
• Flow Type: Gravity, 700ml/min
• Weight: 4.6 ounces

Between the gravity model brands, this is the best solution for the price. It costs less than half compared to Lifestraw models and is more durable than the Lifestraw Family model. Each of the components is versatile on its own. I’ve used the gravity bag as a makeshift handwash station and as a dry bag for storing electronics.

The hose shutoff clip lets you control (or stop) the flow, letting you filter the water as you need it or to use it as a versatile washing/shower station. Filling the bag is easy- you dunk it in water and pull it up with water as close to the MAX line as you can get it. This gives you room to roll the top like a typical dry bag to keep it closed.

Hanging the bag high in a tree helps the water flow rate, and I’ll admit I’ve squeezed it a few times to get it moving a little faster. It’s held up, but I wouldn’t advise squeezing a full bag since you risk making it leak.

Down the line, if you want to upgrade the filter component, you can even attach the gravity bag to a Sawyer Mini or the ITEHIL, which can give you longevity or even more effectiveness, depending on which model you pick. I personally keep the Waterdrop Gravity bag ready to hook up to the Sawyer Mini in my bug out bag.

Even though Waterdrop is a well-known water filter brand, its portable filter shines in survival situations due to its price, effectiveness, and high versatility.

Pick up a Waterdrop Gravity Water Filter and don’t look back- this thing will have your family covered in any disaster scenario.

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Also available to buy at Walmart.

Sure, the Lifestraw personal water filter is great, but it is limited in that it expects you to suck on one end to draw water through the filter. All filtering straws are limited by relying on your lips for flow.

The Sawyer Mini, however, gives you multiple options with the squeeze pouch, straw, and cleaning plunger. This versatility brings it to the top spot for personal water filters. It doesn’t hurt that Sawyer is a reputable brand as well.

Specifications

• Filtration Type: Hollow fiber, 0.1 micron
• Filter Capacity: 100,000 gal (454,609L)
• Flow Type: Multi, 500ml/min
• Weight: 3.5 ounces

Since it’s available in over 5 colors, check each one for a sale or coupon. It’s better to find a good deal than to just get the standard blue filter at full price.

The Sawyer Mini personal water filter accepts plenty of attachments, and it’s even compatible with our top picks’ gravity bag, which lets you increase the capacity and put gravity to work instead of having to squeeze.

I used to suggest the filter package that comes with the squeeze pouch, but more recently changed my recommendation since I don’t believe it is worth the extra $12. You could instead get a gravity bag to attach to it for the same price.

Grab a Sawyer Mini Personal Water Filter for your portable kits, and you won’t regret it.

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Also available to buy at Amazon and Walmart.

It’s been an issue for decades- radionuclides can only be filtered through reverse osmosis, and most reverse osmosis systems are installed and rely on significant water pressure. Now, ITEHIL has flipped all that on its head by developing a battery, pump, and reverse osmosis system all in one compact water filter.

Specifications

• Filtration Type: Reverse osmosis, 0.0001 micron
• Filter Capacity: 100,000 gal (454,609L)
• Flow Type: Battery-powered pump, 500ml/min
• Packed Size: 12″ L x 7″ W x 9″ H
• Weight: 13.2 pounds

This filter can even reduce chlorine for the pool owners out there, adding a potentially huge emergency water source. It has a slew of certifications- FDA, CE, EMC, PSE, FCC, RoSH- but the important cert is the NSF/ANSI 58 that verified reverse osmosis at 100 gallons/day.

The built-in LiFePO4 battery is the perfect size (12,000mAh) to support the pump- it’ll run 27L of purified water before needing a charge. Since originally testing this unit, it has been my go-to water filter, and I’ve never had issues with the battery running short.

The downside is the portability. While it is portable and comes with a handle, it’s tough to carry long distances. The handle is off-center on the top, and the unit gets heavy once the filters are properly saturated, which is necessary for it to be effective.

Using it can be tricky at times- don’t turn it on without the filters installed and the prefilter submerged in some water! Water pumps don’t like to be run dry, and the ITEHIL will turn itself off if it detects a problem. I also wrap the prefilter with cheesecloth to prevent clogs and extend the filter life.

If you need a water filter for any emergency or survival situation, the ITEHIL Powered Reverse Osmosis Water Filter will provide clean drinking water in the worst situations imaginable.

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Also available to buy at Grayl and Walmart.

Most water bottles with integrated filters are like straws – you have to drink through them to filter the water. That’s how straws and other filter bottles can be inconvenient- it’s difficult to filter water for anything but drinking. Grayl flips this on its head by filtering the water with its nested pressing feature, letting you filter a whole bottle in just seconds without having to suck on it.

Specifications

• Filtration Type: Hollow fiber and carbon, 1.25 micron
• Filter Capacity: 40 gal (150L)
• Flow Type: Bottle press, 5,000ml/min
• Packed Size: 3″ D x 9″ H
• Weight: 12.5 ounces

The press filtration is the big feature that makes this bottle stand out. The filtration effectiveness is okay, with a large micron pore size, using the assistance of some carbon filtration. One downside is that it has relatively limited capacity compared to stand-alone filters, with just 40 gallons of water pressed through it until it is expected to clog. The replacement filters aren’t cheap at $25 each, but they are widely available.

The UltraPress has several color choices, but it also has a titanium upgrade you can get, too. Metal water bottles are amazing for survival, and I consider them essential for survival kits. Check out our full review of survival water bottles to see why the UltraPress beat out Lifestraw filter bottles (among others) and to review its comparison metrics relative to other bottles.

Stash a Grayl UltraPress Filter Bottle in your survival kit, or grab one to take on your next ruck through the woods.

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Comparison Table

Survival Water Filter	Recommendation	Price*	Type	Filtration Type	Flow Rate (ml/min)	Weight (oz)
Waterdrop Gravity	Best Overall	$39	Gravity	0.1 micron + carbon	700	4.6
Sawyer Mini	Best for Portability	$17	Straw	0.1 micron	500	2
ITEHIL RO	Best for Worst-Case Scenarios	$299	Powered	Reverse osmosis	500	212
Grayl Ultrapress	Best Filtering Bottle	$75	Press	1.25 micron + carbon	5000	12.5
Membrane Solutions Straw		$13	Straw	0.1 micron	500	2.0
Waterdrop Straw		$14	Straw	0.1 micron + carbon	700	3
Lifestraw Personal		$17	Straw	0.2 micron	3000	1.6
Lifestraw Peak		$25	Straw	0.2 micron	3000	1.7
Lifestraw Peak Solo		$30	Straw	0.2 micron	2900	2
Lifestraw Sip		$35	Straw	0.2 micron	2500	3.5
Sawyer Squeeze		$46	Squeeze	0.1 micron	1700	3
Lifestraw Peak Gravity		$66	Gravity	0.2 micron	3000	8
Survival Filter Pro		$70	Pump	0.1 micron + carbon	500	12.8
Lifestraw Family		$82	Gravity	0.2 micron	200	24
Katadyn Hiker Pro		$95	Pump	0.2 micron	1000	13.4
Survival Filter Pro X		$100	Powered	0.1 micron + carbon	500	13.5
Lifestraw Mission		$120	Gravity	0.2 micron	200	16
MSR MiniWorks EX		$125	Pump	0.1 micron + carbon	1000	16
Bluevua ROPOT		$259	Powered	Reverse osmosis	260	213
Waterdrop K19-S		$309	Powered	Reverse osmosis	130	257
Big Berkey (Using BB9-2)		$367	Countertop	Carbon	110	112

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How I Tested

Water filters are meant to filter water to make it drinkable, so practical testing started with that. I purchased a wide variety of portable water filters over the years to measure, cut apart, and drink from.

Here is how I tested for this review:

• Taste Test: I drank water from each filter at two locations to see how effectively they worked. They each had their challenges with contamination, from roof asphalt runoff to beach sediment. Using the filters multiple times in the same scenarios helped me compare them against each other, rather than relying solely on my experience using them at separate water sources.
  • Rain Barrel: I filtered water out of my rain barrel system, which is connected to my roof.
  • Freshwater Lake: I filtered water from the shore of a nearby lake’s sandy beach.
• Measurement: I measured the water filters with a measuring board and digital scale.
• Cutting Them Open: Lastly, I chopped the water filters in half to see what was going on inside and to verify the manufacturer’s claims.

I did not consider UV pens, boiling, or water-purifying tablets to keep our review focused. Plus, we’ve already reviewed a few of those separately, and they have their place.

We’re always looking for new and better equipment, so if you have a filter that you swear by, let us know down in the comments. We review most of our tested gear annually, so we can always get it in the next roundup and see if it beats out our top picks.

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Why Trust TruePrepper

When survival is on the line, you want gear that works and that you can trust. That’s why I go overboard in our reviews and put these survival water filters through some serious tests.

I’m Sean Gold, and I’ve been testing water filters for over nine years now. When LifeStraw was introduced in early 2014, it shifted how survivalists and preppers viewed water purification.

Now, many years later, we even have portable reverse osmosis machines. As a prepper, all of these options are great for preparedness plans. As an engineer, I enjoyed tearing the filters apart to see how they work.

Besides taking a hacksaw to the filters to check out the internals, I’ve also been field testing them for years by including them in my own car kits, bug out bags, and even just taking them on camping outings. The hacksaw let me quickly see how Lifestraw prioritizes flow rate over filter effectiveness when compared to other filter brands.

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Analysis & Test Results

The best water filters have several important features to look for. To compare our testing data, we assigned weights to the measurements so we could develop an overall score for each filter.

1. Value
2. Filter Effectiveness – 60% of overall score weight
3. Flow Rate– 20% weight
4. Durability – 10% weight
5. Versatility – 10% weight

When you get the right blend of these, you can find a truly reliable water filter that will keep you working through any situation. Below, we break down what each of these features means for a dependable tool that you can trust with your life:

Value: Cost vs. Benefit

The amount of money you spend on something like a water filter shouldn’t blow out your entire budget. Sure, it is important to have access to clean water, but you usually don’t need the most expensive option and only a few redundancies. Budget according to your risk and your needs, rather than just spending lavishly.

On the flip side, you don’t want to go too cheap. Since the commercial success of Lifestraw, there are a ton of Chinese knock-offs that you can find everywhere- from Amazon to the tool store bargain bins. “Buyer beware,” if you plan on trusting your survival to a $5 Lifestraw knockoff.

You never want to spend too much money on one resource, especially something like a filter. It’s better to diversify your tools and preparedness gear to make sure you are covered for a wide range of scenarios. There is a sweet spot where you get high value out of the best features with not too high a price, which is where our top pick sits.

*Price at time of latest update.

Filter Effectiveness

The single most important consideration for a water filter is how well it works, or its effectiveness. A cheap water filter that doesn’t filter down to the micron level won’t help you out and will give you a false sense of security that will end up costing you big.

Membrane Size

The effectiveness of a water filter is usually measured in microns, or how small the openings in the filter are to trap bacteria, viruses, contaminants, etc, but still let water molecules through. This isn’t always the complete story, as the material composition of the filter can also affect how well it filters water. Activated charcoal and ionized materials can work wonders at neutralizing contaminants and not just filtering them.

Most dedicated survival water filters have one type or a combination of these filters:

• 0.1 micron ultrafiltration membrane
• 0.2 micron ultrafiltration membrane
• Carbon filtration
• Reverse osmosis (0.0001 micron)

Our top pick filters down to 0.1 microns, and our portable pick is the same. Neither one is technically 100% effective, but the chances of a pathogen making it through the filter are slim with openings this small. They both test at least 99.9999% effective, which is a one-in-a-million chance of a single pathogen making it through the filter.

Filtration Limits

Unfortunately, for most filters, one restriction is radionuclides, which can only be filtered with reverse osmosis systems. These typically take some pressure to use and are less portable, but a few companies focused on using ingenuity to find solutions now give us some options.

In survival situations, water filters can also become clogged. Some larger filters, like the ITEHIL or Lifestraw Family, have exhaust water tubes, where dirty water is flushed out in a separate outlet from the clean water. This helps the filters stay less clogged, since they are constantly being washed.

Smaller straw-style filters do not have these built in. The Sawyer Mini includes a syringe to push water through in reverse. Sometimes, you can blow on the end to push clogs out, though that is much less effective for long-term filter life. We discuss this further in the filter maintenance section below.

Flow Rate

The amount of water that can move through the filter (typically measured in milliliters per minute) is called the flow rate. This is a function of the size of the filter and how the membranes and substrates restrict the flow.

Although many straw filters show high flow rates, those rates are not attainable with regular human suction. Many straw filters are difficult to pull water through for extended periods, depending on the condition of the water.

All of this is different than storage capacity, though that is important to consider since it can determine how much water you can filter at once. The larger the capacity, the less you have to refill and pay attention to the filter as it is working.

Luckily, all of our picks have higher capacity add-ons, purchase options, or even hacks that you can do – even the portable Sawyer MINI!

Planning for your capacity needs ahead of time can help, and you can use our water storage calculator from our water storage guide to predict how much clean water you’ll need for yourself and your family.

Durability

The last thing you want is to have an excellent water filter but have it break on you when you need it most. All of our picks are durable ABS plastic or stainless steel, so you shouldn’t have issues with cracking or breaking the casings unless you are extremely hard on them. Limit the plastic casing’s sun exposure to prevent it from becoming brittle over the years.

I took the filters apart with a hacksaw and compared the durability. Ones with glass components brought up the rear, while overbuilt small filters without moving parts topped the competition.

You should clean the filters regularly and avoid using highly contaminated water since it will clog the filters and/or reduce their lifespan. If you plan on getting water from very dirty sources, consider using a cheesecloth pre-filter to keep sediment out of your drinking water filter.

Versatility

One of our picks was buoyed to the top because of its versatility. Whenever you consider survival tools, you’ll need them to work for you in a variety of situations. When it comes to water filters, versatility is being able to filter water using suction (straw), gravity feed, or forcing water through the filter (squeeze).

Accessories

In extreme situations (or where you encounter redundancies), water filters can be repurposed into siphons and containers for non-water liquids. Of course, this isn’t condoned by any manufacturer, but with a syringe pump, length of tubing, gravity feed bag, or any other accessory that comes with a water filter, a resourceful prepper will find plenty of versatile uses.

Size & Weight

We typically have size and weight as a separate measurement for our overall score, but for water filters, we included it in the versatility since those were heavily dependent on how the filter is intended to be used (ex: a straw’s weight compared to a powered RO system is not a useful comparison since the latter will not be used in a bug out bag).

Ergonomics

The ergonomics of survival water filters lend to their portability and use. Most small water filters are easy to carry and use, but the large ones can be unwieldy. I can’t tell you how many times I’ve had the Lifestraw Family basket filter fall out of it while I’m carrying it.

Also, the off-center handle on the ITIHEL can be annoying when you carry it long distances, especially once it’s saturated with water and heavy. The Grayl Ultrapress has the best ergonomics, since it’s designed to be carried in your hand. It has a grippy, slip-resistant texture and a retention ring built into the cap. This pays off since you have to lean most of your body weight on the bottle to press the filter down.

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How to Use a Survival Water Filter

Charcoal filters were first patented in the mid-1700s, but people have been filtering water to make it clean to drink for as long as they have been collecting it. Each filter has its quirks, and squeeze filters work differently from gravity filters.

The Goat Mumbler does an excellent job breaking down our top portable pick and demonstrating how to use it to its maximum potential:

SAWYER MINI WATER FILTER SYSTEM & HACKS

Filter Maintenance

Some filters, like the Lifestraw Family, Mission, and ITEHIL reverse osmosis, have outlet valves for wastewater. This is great because it doesn’t require as much backflow cleaning, but it does require attention, so you don’t get water everywhere.

I don’t advise keeping the wastewater in a container to re-filter- I’ve found that to be a pointless way to clog filters faster. Even when every drop of water counts, the filter pushes out that waste for a reason.

Syringes are typically used to clear up clogs in straw-type filters that don’t include outlet valves. The syringe simply pushes water through the opposite direction, which opens up some of the clogged microscopic pores in the membrane.

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Who Needs a Water Filter?

Water filters are a prepping and survival staple, but they have started to go mainstream thanks to the marketing and philanthropic efforts of companies like Lifestraw and Sawyer. Lifestraw, in particular, created suburban demand for its filters that caused a wave of blue imitators, which in turn drove down prices.

Now, water filters are needed for survival and are much more affordable.

This is why you’ll find it suggested for almost every kit.

Water filters are essential for:

• Home Survival Kit
• Bug Out Bag
• Get Home Bag
• INCH Bag
• Bug Out Vehicle

We suggest a water filter for these kits as well:

• Everyday Carry
• Car Kits

Of course, you can always use a water filter for things beyond emergencies and survival kits, too, like rugged camping and bushcraft or family get-togethers. We actually encourage it- don’t let the filter sit in your kits without knowing how it works or how to use it properly.

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Sources & References

All of our experience and the testing we do to determine the best water filter are useless without listing our research sources and references. We leaned on these for the book knowledge that we paired with our hands-on testing and practical military and prepping experience:

Logsdon, G. (1990). Microbiology and Drinking Water Filtration. McFeters, G.A. (eds) Drinking Water Microbiology. Brock/Springer Series in Contemporary Bioscience. Springer, New York, NY. Pages 120 – 146. (Source)

Montaña, M., et al. (2013). Removal of radionuclides in drinking water by membrane treatment using ultrafiltration, reverse osmosis, and electrodialysis reversal. Journal of Environmental Radioactivity. Volume 125. Pages 86 – 92. (Source)

Shen, C., et al. (2021). Construction of portable drinking water device using an agricultural biomass-derived material of polyethylenimine-grafted-corncob. Food Control. Volume 130. (Source)

Walters, A. (2008). A performance evaluation of the LifeStraw: A personal point of use water purifier for the developing world. The University of North Carolina at Chapel Hill ProQuest Dissertations Publishing. (Source)

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Conclusion

Water is important for survival, and clean water is difficult to find in emergencies. Many people rely on a city tap or electric wells that aren’t as robust as you may think. Make sure you have a water storage plan and a way to replenish water over extended periods.

To go along with a solid water filter, you should also consider a few other tools to help with your emergency water plans:

• The Best Water Purification Tablets for Emergencies and Survival
• The Best Rain Barrel for Prepping and Emergencies
• Home Survival Kit List | 53 Essentials

See more of our expert-written guides, resources, and reviews in your search results – add TruePrepper as a preferred source.

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