Squeeze Based Ultralight Water Filters & The Vessels To Pair Them With
After thoroughly analyzing the marketplace and testing most possible combinations, we can officially say that these are the best squeeze based ultralight water filters for backpacking. This guide takes into account not just the filter units, but which vessel to pair each with, what they’re best at, and where in your pack to store them.
Hop onto the PCT this summer and you’ll see that virtually every thru-hiker is using an ultralight squeeze filter. That’s because they’re the fastest, simplest, and most reliable system for both soloists and groups (so long as everyone has their own). As such, we have excluded all of the outdated or nonsensical options, including pumps, straws, UV pens, and gravity-based system. Chemical treatments work great, but aren’t featured here because this guide is specific to ultralight water filters.
Keep scrolling to grok the recommendations, and while you’re here, don’t miss our guide to water bladders, ultralight bottles, sustainable bottles, shoulder strap sleeves, soft flasks, and the complete water storage system.
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Filter + Bottle Combo Quick Picks
The 4 Best Ultralight Water Filters
- Best Overall, Most Reliable Filter System: Sawyer Squeeze + Cnoc VectoX 2L
- Best Filter for Front Mounting: HydraPak UltraFlask + Filter Cap .5L
- Best Hard-Sided Filter, All-In-One: HydraPak Breakaway 900ml Filter Bottle
- Best Hard-Sided Filter, Interchangeable System: Sawyer Squeeze + Igneous NOBO
Top Pick Ultralight Water Filters
- Filter For Front-Mounting: Katadyn BeFree AC .5
- Versatile Soft Flask Filter: Katdyn BeFree AC 1L Double Layer
- Versatile Soft Flask Filter: LifeStraw Peak Squeeze 32oz
- Collapsible Semi-Rigid Filter: HydraPak 42mm Filter 1.5L Flux
- Collapsible Semi-Rigid Filter: HydraPak 42mm Filter Cap + Cnoc Vesica 1L 42mm
- For Filtering Into Clean Bottles: HydraPak 42mm Filter Cap + Cnoc VectoX 2L 42mm
- For Filtering Into Clean Bottles: HydraPak 42mm Filter Cap + HydraPak Seeker 2L
- For Filtering Into Clean Bottles: Platypus QuickDraw + Cnoc VectoX 2L 28mm
Comparing Ultralight Water Filters
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| Model | Price ($) | Capacity (L) | Weight (oz) | Cap Threading (mm) |
| Sawyer Squeeze + Cnoc VectoX | 65 | 2.1 | 6.3 | 28 |
| HydraPak UltraFlask Filter Cap | 50 | 0.5 | 2.3 | 42 |
| HyrdaPak Breakaway Filter Bottle | 48 | 0.9 | 4.2 | 63 |
| Sawyer Squeeze + Igneous NOBO | 67 | 1.0 | 5.3 | 28 |
| Katdyn BeFree AC | 45 | 0.5 | 2.5 | 42 |
| Katdyn BeFree AC Double Layer | 53 | 1.0 | 3.0 | 42 |
| LifeStraw Peak Squeeze | 44 | 1.0 | 3.9 | 42 |
| HydraPak 42mm Filter + Flux Bottle | 55 | 1.5 | 5.0 | 42 |
| HydraPak 42mm Filter + Cnoc Vesica | 52 | 1.0 | 4.1 | 42 |
| HydraPak 42mm Filter + Cnoc VectoX | 60 | 2.1 | 5.2 | 42 |
| HydrapPak 42mm Filter + HydraPak Seeker | 60 | 2.0 | 4.7 | 42 |
| Platypus QuickDraw + Cnoc VectoX | 65 | 2.1 | 6.1 | 28 |
The 4 Best Ultralight Water Filters
Sawyer Squeeze + Cnoc VectoX 2L
Sawyer Squeeze + Cnoc VectoX 2L 28mm is widely considered to be the most reliable filter-bladder combo in existence, and we agree 100% with that sentiment. It pairs the most durable and user-friendly reservoir (Cnoc VectoX) with the longest lasting and most-proven filter (Sawyer Squeeze) to create a system that holds up to at least five months or 2650 miles of non-stop daily use. Hop on the PCT and you’ll note an overwhelming majority of thru-hikers use it. Enough said.
The Cnoc VectoX is a thickened and more durable version of the original Vecto, and its secret sauce is twofold: firstly, the leak-proof top opens up for quick and easy filling; and secondly the bottom end fits a Sawyer Squeeze filter. No tubes or other finnicky components. The Sawyer is the original squeeze filter, and still the most trusted because of its exceptionally long lifespan (rated to filter 100,000 gallons) and how well it responds to back flush cleaning.
The best use-case for this system is to store it empty in an external pocket throughout the day, using it to filter water into clean bottles during breaks. It does double duty as a reservoir for cameling up. Its biggest downsides are the fact that the Sawyer protrudes awkwardly at a right angle, the system isn’t good for direct drinking, and that it’s slightly heavier than similar alternatives, though still lightweight in the grand scheme of things.
- Price: $65
- Weight: 6.3
- Cap Threading: 28mm
- Purpose: Filtering into other bottles
- Stow: Any external pocket if empty, side pocket or top of pack if full
- Pros: Most reliable, most durable, longest lifespan. Easy to fill. Responds well to back flush. Filters two 1L bottles per fill-up. Collapsible.
- Cons: Bulky filter protrudes awkwardly. Heaviest unit by a small margin. Bad for direct drinking.
HydraPak UltraFlask Filter Cap 500 ml
If you like front mounting soft flasks, then you’ll love the new-for-2025 HydraPak UltraFlask with a bite valve filter cap, replacing Katadyn BeFree as our top pick for on-the-go hydration. This unit is one of only two bite valve-style soft flask filters we’re aware of, and it fits perfectly into shoulder strap and vest pockets; this unit was designed for trail running. Fill it up as you pass by any source and you’ll never have to stop for a dedicated water filtering break again.
What’s more, it’s faster to drink from than BeFree or HydraPak’s 42mm filter head, because there is no cap to twist or flip open, and you can even drink from it without taking it out of the front pocket. Lastly it comes with a minimalist backflush tap that weighs just a couple of grams and attaches to any 28mm threaded bottle. The UltraFlask represents a new generation of ultralight water filters for backpacking.
As far as we can tell, the price and filter head is identical to Salomon Soft Flask XA Filter, but we prefer the shape of HydraPak’s UltraFlask.
- Price: $50
- Weight: 2.3 oz
- Cap Threading: 42mm
- Purpose: Direct-to-mouth drinking on the go
- Stow: Front-mounted
- Pros: Best front-mounted filter. Bite valve is faster than caps. Cleans via swish/shake or its own UL backflush tap. Collapsible.
- Cons: Less reliable, shorter lifespan than Sawyer Squeeze. Low volume means more effort to fill other bottles. Doesn’t stand upright.
HydraPak Breakaway Filter Bottle 900 ml
Step aside Sawyer + Smartwater, there’s a new best hard-sided filter bottle in town. Meet the new for 2025 HydraPak Breakaway 900 ml, a filter that was designed for mountain biking but is just as relevant for hiking. While acknowledging that Sawyer + Smartwater remains the most reliable, long-lasting, and trusted system, the HydraPak Breakaway either ties or bests it on every other usability axis.
Firstly, the Breakaway weighs and costs roughly the same, but its filter head is sunken into the neck of the bottle, which makes it significantly shorter and easier to drink from. The top of the Breakaway is as tall as top of a Smartwater before screwing on an additional 5″ of sawyer filter. Ergo, it’s less top heavy and better balanced. Furthermore, Breakaway has a unique “self-burping feature,” which allows air to re-enter the bottle as you drink, eliminating the need to stop and manually let air in. It also comes with HydraPak’s 2g back flush tap, and responds to both swish/shake cleaning, and backflushing. Lastly, it has a better flow output, at least at first, than Sawyer Squeeze. Though mid-way through its life, Sawyer closes the gap.
The Breakaway is good for filtering into other bottles, and even better for direct-to-mouth drinking. Store it in a side pocket. A 600 ml version is also available and good for front mounting, though not as good as the aforementioned UltraFlask bite valve filter.
Pro tip: remove the muck guard; hikers don’t need it.
- Price: $48
- Weight: 4.2 oz
- Capacity: 900ml
- Cap Threading: 63mm
- Purpose: Direct drinking or filtering into others
- Stow: Side bottle pocket
- Pros: Best hard-sided filter. Durable. Stands upright. Self burping. Easier to use than Smartwater + Sawyer.
- Cons: Not collapsible. Less reliable, shorter lifespan than Sawyer Squeeze.
Sawyer Squeeze + Igneous NOBO 1L
Replacing the iconic (yet reprehensible) Smartwater, we now recommend the combination of Sawyer Squeeze + Igneous NOBO as the best interchangeable filter/bottle combo. This creates a healthier, more ethical, and more sustainable version of the most popular pairing on the PCT. Sawyer Squeeze filters last practically forever (rated to 100k gallons), respond well to back flushing, and can be interchangeably moved between any 28mm threaded vessel like Igneous NOBO.
Igenous NOBO is an ounce heavier than the 1L Smartwater, but still only 2.3 oz, and made with reusable HDPE plastic instead of PET. Ergo it is more durable, longer lasting, less affected by UV degradation, and less prone to microplastic shedding. Physically, it’s a bit shorter and wider than Smartwater, but still narrower than Nalgene. What’s more, it has very visible volume indicators for pouring measured amounts, and an incredibly burly and thoughtful cap-and-tether system. NOBO is the new best reusable UL bottle, and best vessel with which to pair a Sawyer Squeeze. If you’re pushing super ultralight, the ounce of weight savings may still justify Smartwater.
- Price: $67
- Weight: 5.3 oz
- Capacity: 1L
- Cap Threading: 28mm
- Purpose: Direct drinking or filtering into others
- Stow: Side bottle pocket
- Pros: Ultra reliable. Responds to backflushing. Utilizes the new best UL hard bottle, not use single-use plastic. Great volume indicators. Easy grip cap stays tethered.
- Cons: Tall, awkward, unbalanced, unwieldy when filter is mounted. Requires frequent burping. Heavier than Smartwater.
More Top Pick Ultralight Water Filters
Katadyn BeFree AC .5L
Katadyn BeFree was the first ever soft flask filter and one of the original ultralight water filters. It remains a good option to this day, though is no longer the best for front mounting. The new-for-2025 Katadyn BeFree AC adds a number of improvements to the system, including a much tougher flip top lid, a handling loop, and the option for activated carbon filtration to improve taste. The AC tech filters out the taste of tannins and other unwanted flavors that the primary hollow fiber filter won’t catch. While this is nice to have, it slows the flow rate so we recommend removing the activated carbon tab unless it’s needed. To be honest, it’s mostly a gimmick.
The downsides to BeFree are that it is built with the thinnest TPU soft flask material, has a shorter lifespan than Sawyer, and does not accommodate back flush cleaning.
- Price: $48
- Weight: 2.3 oz
- Cap Threading: 42mm
- Purpose: Direct-to-mouth drinking on the go
- Stow: Front mounted
- Pros: Ultralight. Filters out bad tastes. Front mounts well. Sturdy cap.
- Cons: Not very durable. Less reliable, shorter lifespan than Sawyer Squeeze. Taste filtration doesn’t matter much, slows flow rate (but can be removed). No back flush.
Katadyn BeFree AC Double Layer1L
Jumping up to the 1L capacity soft flask genre, we recommend switching to the Double Layer edition of Katadyn BeFree AC, which is built with a thicker TPU material that eliminates many of the durability concerns associated with the base version. The 1L sized BeFree is better than the half liter when it comes to filtering into other bottles, but more awkward to drink from directly, and doesn’t fit well into front pockets. Knowing that you’ll side mount it, that slot runs up against some pretty stiff competition including HydraPak Breakaway 900 and Sawyer + Smartwater. Like the base version, AC Double also does not allow for backflushing and is harder to clean once seriously clogged. It does not come in half liter sized version.
- Price: $53
- Weight: 3.0
- Cap Threading: 42mm
- Primary Purpose: Direct drinking or filtering into others
- Stow: Side pocket
- Pros: Durable. Filters out bad tastes. Sturdy cap.
- Cons: Less reliable, shorter lifespan than Sawyer Squeeze. Taste filtration doesn’t matter much. No back flush.
LifeStraw Peak Squeeze 1L
LifeStraw Peak Squeeze is another Katadyn BeFree clone, and one of many ultralight water filters worth considering. For starters, it comes with many of the same advantages, including collapsible body and high flow rate. It’s built with a more durable TPU body (approx equal to the double layer version), gets higher average review scores on REI, and perhaps most importantly it is compatible with backflush cleaning. The Peak Squeeze comes with a really nice syringe. This unit is like what you’ve seen from Sawyer Squeeze, only it’s more compact, and screws into the head of the Peak Squeeze for more effective flushing.
Like BeFree 1L, the major downsides to this unit are that it’s too large to front mount and still less reliable and long lasting than Sawyer Squeeze. The LifeStraw Peak Squeeze .6L version is front-mountable, but wider than others like it and doesn’t situate into pockets quite as well.
- Price: $44
- Weight: 3.9 oz
- Cap Threading: 42mm
- Primary Purpose: Direct drinking or filtering into others
- Stow: Side pocket
- Pros: Versatile. Durable. Highly rated. Back flush cleaning, good backflush syringe.
- Cons: Less reliable, shorter lifespan than Sawyer Squeeze. Too large to front mount.
HydraPak Flux Filter Bottle 1.5L
The HydraPak Flux 1.5L is a filter bottle unlike any other. It is a soft-hard hybrid design, capable of standing upright on its own, and also compressing down when empty. While that combination of characteristics is highly desirable, it doesn’t do either particularly well. Sure, it stands up right when full, but flops over constantly half full, unless you burp it to let air back in. It compresses down, but is bulkier than any of the other compressible options.
The good news is that it’s quite durable, much more so than any of the soft flasks, but so less than any of the hard bottles. Because it collapses as you filter out of it, it is a good device for filtering into other bottles; okay but kind of awkward to drink out of directly. Many backpackers swear by the flux, and it’s certainly interesting. But we’ll admit we don’t reach for it often. A mixture of true hard-sided and true soft sided bottles makes for a better overall system than semi-rigid hybrids.
- Price: $55
- Weight: 5.0 oz
- Cap Threa1ding: 42mm
- Primary Purpose: Direct drinking or filtering into others
- Stow: Side pocket
- Pros: Versatile. Durable. Highly rated. Stands upright and collapses.
- Cons: Floppier than hard bottles, less collapsible than soft bottles. Less reliable, shorter lifespan than Sawyer Squeeze. Does not back flush.
HydraPak 42mm Filter + Cnoc Vesica 1L
The Cnoc Vesica is another take on the hard-soft hybrid bottle design, but approaches it completely differently from the aforementioned HydraPak Flux. While the Flux is built with a single material that is both malleable and structural, the Vesica utilizes traditional hard-sided plastic on the top and bottom sections, with traditional soft flask material along the side walls. As such, it is even more collapsible, but also floppier and does a worse job of standing upright on its own.
Notably, it’s a bit lighter weight than Flux, and its narrower cylindrical shape better accommodates front-mounting if you have a large enough sleeve. We recommend the 42mm version with a HydraPak 42 or BeFree filter attached over the 28mm + Sawyer, because the latter option makes it taller, floppier, heavier, and even more unwieldy.
- Price: $52
- Weight: 4.1 oz
- Cap Threa1ding: 42mm
- Primary Purpose: Direct drinking or filtering into others
- Stow: Side pocket
- Pros: Lightweight. Versatile. Stands upright when full. Collapses when empty.
- Cons: Floppy and awkward. Less reliable, shorter lifespan than Sawyer Squeeze. No back flush.
HydraPak 42mm Filter + Cnoc VectoX 2L
For another take on the famed Sawyer x Cnoc combo, consider instead pairing a HydraPak 42mm filter head with Cnoc VectoX 2L. Because of how 42mm filters are sunken into the neck of the vessel (instead of protruding 5″ off the top like Sawyer), this system packs down smaller and is less unwieldy to use. This style of filter also benefits from a faster up-front flow rate, but degrades in the long term, can’t be back flushed, and will need to be replaced long before a Sawyer Squeeze. But in the short term, it is lighter weight and easier to use.
Pro tip: all ultralight water filters that work with HydrPak 42 mm also works with Katadyn BeFree AC. However, with the BeFree, you are forced to buy the complete flask system, or all three filter head components separately (filter, lids, and activated carbon tabs). Not worth the extra effort and $5-10.
- Price: $60
- Weight: 5.2 oz
- Cap Threa1ding: 42mm
- Primary Purpose: Filtering into other bottles
- Stow: Any external pocket if empty, side pocket or top of pack if full
- Pros: Lightweight. Great for filtering into other bottles. Top opens for easy fill up. Durable. Compact shape thanks to sunken filter unit.
- Cons: Less reliable, shorter lifespan than Sawyer Squeeze. No back flush. Not good for direct drinking.
HydraPak 42mm Filter + HydraPak Seeker 2L
For a second alternative to the Sawyer x Cnoc combo, consider replacing the VectoX with a HydraPak Seeker 2L, still paired with a 42mm filter cap. This ultralight reservoir has some advantages, including a slightly lighter weight build and a really nice handle, which makes it easy to drag through a water source without fully submerging your hands.
Pair it with a HydraPak 42mm filter, which has a higher upfront flow rate and protrudes way less than Sawyer Squeeze, making it overall easier to use and smaller to stow. However, it’s not as good as a Sawyer in the sense that it rated for a shorter lifespan and cannot be backflush cleaned.
- Price: $60
- Weight: 4.7 oz
- Cap Threa1ding: 42mm
- Primary Purpose: Filtering into other bottles
- Stow: Any external pocket if empty, side pocket or top of pack if full
- Pros: Lightweight. Great for filtering into other bottles. Durable. Handle and wide opening makes fill up easy. Compact shape thanks to sunken filter unit.
- Cons: Less reliable, shorter lifespan than Sawyer Squeeze. No back flush. Not good for direct drinking.
Platypus QuickDraw + Cnoc VectoX 2L
While Sawyer x Cnoc remains the filter reservoir combo to beat, Platypus QuickDraw x Cnoc is a third and final alternative system. Platypus QuickDraw is identical to Sawyer in virtually every way, shape/weight/function/etc, and offers very little distinction in terms of advantages and disadvantages, especially when paired with the same reservoir.
As far as we can tell, the main difference is that it gets lower customer review scores at REI due to quality control; there seems to be a slightly higher chance of having a new filter not work. That being said, some very respected gear heads swear by the QuickDraw, so while we don’t prefer it, we won’t fault you for using it instead of Sawyer.
- Price: $65
- Weight: 6.1 oz
- Cap Threa1ding: 28mm
- Primary Purpose: Filtering into other bottles
- Stow: Any external pocket if empty, side pocket or top of pack if full
- Pros: Reliable, durable, long lifespan. Easy to fill. Responds well to back flush. Filters two 1L bottles. Collapsible.
- Cons: Bulky filter protrudes. Heavier than average. Bad for direct drinking. QuickDraw is very similar to Sawyer Squeeze but less well regarded.
Front-mountable filters, L-to-R: HydraPak UltraFlask, Katadyn BeFree AC .5L, Breakaway 600ml, LifeStraw Peak 22oz
Backpacking Water Filters We Excluded
While many of the below are considered ultralight water filters, they fail on other axis, including efficiency, reliability, user-friendliness, and functionality.
All Pump Filters: Pump filters are a relic of days gone by, and no longer relevant to the modern hiker. Simply put, squeeze-based filters are easier and faster to use, and more reliable. Never purchase a pump filter.
All Gravity Filters: While gravity filters have relevance to group base camping, they are bad for filtering on the go. The fastest and most efficient group system is if everyone carries and manages their own squeeze based system.
All UV Pens: UV pens are not reliable enough, have finnicky parts, and do poorly with really dirty water. Never use UV filters.
All Straw-Based Filters: It’s hilarious to think somebody would filter straight out of a water source when they could instead put that water into a 1-3 ounce vessel and drink from it at their leisure. Never purchase straw-based filters.
All Chemical Treatments: Chemical treatments are ultralight, and ultra reliable because they don’t have parts that can break, ableit less/not effective at treating cryptosporidium. However, this is a guide to backpacking water filters, so chemical treatments like AquaMira and AquaTabs were categorically excluded.
Sawyer Squeeze Micro & Mini: These have all of the same upsides and downsides as Sawyer Squeeze Original, but are smaller and less bulky with the drawback of lower flow rates and less trusted by thru-hikers. Because the main reason to choose a protruding Sawyer-style filter is reliabilty not weight/bulk savings, the Micro and Mini aren’t worth it. If you prefer the lightest/least bulky option, choose a 42mm sunken filter unit like HydraPak or BeFree, which protrude far less off the top of the vessel. Mini and Micro exist in a no-man’s land.
Platypus DayCap: Only works with heavy hard-sided bottles like Nalgene, must be sucked, can’t be squeezed, can’t be used to filter into other vessels. Don’t use this one.
HydraPak 28mm Filter: It seems like this filter is designed to attach to tubing for a hydration reservoir system. It’s flimsier than Sawyer Squeeze and Platypus QuickDraw, so we recommend avoiding it.
Grayl GeoPress: Despite rave reviews from travelers, this filter bottle weighs a pound and should be avoided at all costs. Do not consider this as a valid option for backpacking when similar systems weighs 25% as much.
L to R: Breakaway 900, Sawyer + Smartwater 1L, HydraPak Flux 1.5L, Lifestraw Peak 22oz, Cnoc Vesica + BeFree
Pro Tips For Choosing and Using Ultralight Water Filters
Filter selection by trip duration: In short, the longer your trip is, the more likely you should be to choose a Sawyer Squeeze. Because it’s the longest lasting, most reliable, most cleanable, and most proven filter, it is the best option for section hikes and thru-hikes. That being said, it’s also the heaviest, bulkiest, and most unwieldy model that protrudes off the top of your vessel more than other. It also has the slowest flow rate when new, much slower than a new BeFree, for example. So for shorter trips while you have access to fresh gear in good condition, and when longevity is prioritized lower, a non-Sawyer Squeeze filter with a back-up for redundancy is best.
AquaTabs as backup: Any filter, even a Sawyer Squeeze can fail. Soft flasks can puncture, Sawyer can lose its O-ring, and all filters are rendered useless if left out to freeze. We recommend carrying a 10 pack of AquaTabs as a backup. These ultralight tablets weigh just 0.1 oz, and work like AquaMira (but aren’t approved to kill cryptosporidium). Store with your first aid/repair kit.
HydraPak backflush tap: We’ve been very satisfied with the HydraPak backflush tap which weighs just 0.1 oz. It screws onto any 28 mm threading and can be used to just like the syringe. Squeeze water through it and into the mouth of the filter to purge gunk out of the inner workings.
L to R: QuickDraw + Platy 2L, Sawyer Squeeze + Cnoc VectoX, HydraPak 42mm + HydraPak Seeker, BeFree + Cnoc VectoX
Ultralight Water Filter Conclusion
Thank you for reading our guide to ultralight water filters, where we hope you found your next purification solution. We’re always testing new filter-bottle combinations, so a drop us a line in the comments if you have a suggestion. Happy hiking, and happy hydrating!
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