Top 5 compared
The best water filter straws
Clean drinking water from a mountain stream or lake, without carrying every drop from home.
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The top 5 at a glance
A portable water filter traps bacteria as stream or lake water passes through it. Filter straws are the simplest: you drink through them straight from the source. Others screw onto a bottle or a soft squeeze pouch, which lets you fill a clean bottle for later or to share, or sit in the lid of a soft flask you drink from.
Most catch parasites such as Giardia as well as bacteria. None of these says it stops viruses, and none claims to make seawater drinkable, so they’re meant for streams, lakes and other fresh water. Each needs cleaning now and then to keep the water flowing, by backflushing or shaking as its maker says.
What matters
- A filter life in gallons, as rated by the maker.
- Threads that fit ordinary disposable water bottles.
- A carbon stage, if taste and smell matter.
- A weight of a few ounces, for a light pack.
#1LifeStraw Personal Water Filter
$10–$20
Put one end in a stream or lake and sip, and the water is filtered on its way up, with nothing to pump or charge. TIME named it one of the best inventions of 2005.
What owners say: Small and light enough to go on every trip and to sit in the emergency kit, it makes backpacking easier, and some call it a lifesaver in a tight spot.
Heads up: Drinking through it takes a firm, steady sip, so give it a try at home before the trip.
A closer look: LifeStraw designs it for germs, microplastics and silt, not chemicals or heavy metals, so it’s for fresh water from streams and lakes. Blow back through the mouthpiece after drinking to clear the water out, as LifeStraw advises, and it’s light enough to live in the emergency kit too.
- Drink straight from the source
- No pumps, batteries or chemicals
- Filters down to 1 micron
Best for: A simple straw for the pack
- Filters up to
- 1,000 gal
- Removes (maker)
- Bacteria, parasites, microplastics
- Weight
- 1.6 oz
- Screws onto a bottle
- No
- Bottle or pouch included
- No
#2Sawyer Mini Water Filtration System (with pouch and straw)
$20–$30
A palm-sized filter that screws onto the supplied squeeze pouch or a standard disposable water bottle, fits inline on a hydration pack, or works as a straw, and Sawyer rates it for up to 100,000 gallons.
What owners say: Light, compact and simple to use, it screws onto ordinary soda bottles and sits neatly in a pack, and some keep one in a go-bag for emergencies.
A closer look: Squeeze dirty water from the pouch through the filter into a clean bottle to filter for the whole group. When the flow slows, push clean water back through it with the cleaning plunger in the box, which is what keeps it going for so long.
- Filters to 0.1 micron
- Also works as a straw
- Inline on a hydration pack
- Cleaning plunger in the box
Best for: Filling bottles for a group
- Filters up to
- 100,000 gal
- Removes (maker)
- Bacteria, protozoa, microplastics
- Weight
- 2 oz
- Screws onto a bottle
- 28mm bottles
- Bottle or pouch included
- 16 oz pouch
#3Practical Survival Water Filter Straws (2-pack)
$30–$50
Two filter straws in one pack, one for the backpack and one for the car or the emergency kit. Each removes over 99.99% of bacteria and parasites through a 0.1-micron membrane, weighs 2 oz and lasts for up to 1,800 gallons.
What owners say: Many keep a pair in an emergency kit, and they find the straws easy to use, light and sturdy. Taste is the mixed point: fine for some, while others notice a plastic flavor.
A closer look: Each straw comes sealed with its own plunger: push clean water back through it after a trip to clear the membrane and keep the flow going. With two in the pack, one can stay in the car or the go-bag while the other goes hiking.
- Two straws in a pack
- Plunger to clean each straw
- 0.1-micron membrane
- 8 in long
Best for: Emergency kits and the car
- Filters up to
- 1,800 gal
- Removes (maker)
- Bacteria, parasites, microplastics
- Weight
- 2 oz
- Screws onto a bottle
- –
- Bottle or pouch included
- No
#4Membrane Solutions S1 Water Filter Straw
$10–$20
A carbon stage on top of a 0.1-micron membrane improves the taste as well as filtering, and both ends unscrew for backwashing, which is how it reaches its 1,320-gallon rating.
What owners say: Pocket-sized and well made, it filters well and has earned a place in plenty of survival kits. How long it lasts is the open question: long-lived for some, while others have doubts.
A closer look: The carbon stage takes out odd tastes and smells but leaves the water’s minerals alone. Screw it onto a water bottle filled from the stream rather than lying down at the bank to drink; it filters about two cups a minute, quick enough to sip on the move.
- Carbon layer takes out smells
- Both ends open for backwashing
- About two cups a minute
- Leaves the water’s minerals in
Best for: Better-tasting stream water
- Filters up to
- 1,320 gal
- Removes (maker)
- Bacteria, microplastics, chlorine taste
- Weight
- 2 oz
- Screws onto a bottle
- 28mm bottles
- Bottle or pouch included
- No
#5Katadyn BeFree 1.0L Water Filter Bottle
$30–$50
A soft 1-liter flask with the filter in the lid: fill it from a stream and drink as you go at up to 2 liters a minute, then roll it flat into a pocket. At 2.2 oz it suits trail runners and light-packing hikers.
What owners say: Quick to filter and easy to use, it packs small enough for a carry-on and suits backpacking. The soft flask is the weak spot, with several springing a leak within weeks, and views on the price are mixed.
Heads up: Katadyn now also makes the BeFree AC, which adds a carbon stage for better-tasting water; its cartridges fit this flask, so you can upgrade later.
A closer look: Shake or swish the filter in water to keep the flow fast, as Katadyn advises; there’s no backflushing and no tools. Keep the soft flask away from sharp edges in the pack, and fit a new cartridge when shaking no longer brings the flow back.
- Up to 2L a minute
- Rolls flat into a pocket
- Shake to clean, no tools
- 0.1-micron filter in the lid
Best for: Trail running and fast hikes
- Filters up to
- 264 gal
- Removes (maker)
- Bacteria, cysts, sediment
- Weight
- 2.2 oz
- Screws onto a bottle
- No
- Bottle or pouch included
- 1L soft flask
How they compare
Swipe sideways or rotate device to see all 5.
| Feature | #1LifeStraw | #2Sawyer Mini | #3Practical Survival | #4Membrane Solutions S1 | #5Katadyn BeFree |
|---|---|---|---|---|---|
| Best overall | Most versatile | Best budget | Best for trail running | ||
| Picked Rating | 9.7 | 9.4 | 9.3 | 9.3 | 9.0 |
| Price | $10–$20 | $20–$30 | $30–$50 | $10–$20 | $30–$50 |
| Filters up to | 1,000 gal | 100,000 gal | 1,800 gal | 1,320 gal | 264 gal |
| Removes (maker) | Bacteria, parasites, microplastics | Bacteria, protozoa, microplastics | Bacteria, parasites, microplastics | Bacteria, microplastics, chlorine taste | Bacteria, cysts, sediment |
| Weight | 1.6 oz | 2 oz | 2 oz | 2 oz | 2.2 oz |
| Screws onto a bottle | No | 28mm bottles | – | 28mm bottles | No |
| Bottle or pouch included | No | 16 oz pouch | No | No | 1L soft flask |
| Best for | A simple straw for the pack | Filling bottles for a group | Emergency kits and the car | Better-tasting stream water | Trail running and fast hikes |
| Buy now | Amazon | Amazon | Amazon | Amazon | Amazon |
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