In-Depth Comparison: SteriPEN vs LifeStraw for Outdoor Enthusiasts

Water filters are essential for backpackers, campers, and survival kits. Two of the most common are LifeStraw and SteriPEN. At first glance, they may seem very similar, but they’re very different.

The LifeStraw is an easy-to-use straw-style water filter that removes bacteria and protozoa. The SteriPEN is a UV water purifier that kills bacteria, protozoa, and viruses 1 liter of water at a time but doesn’t filter water.

Let’s look at the strengths and weaknesses of LifeStraw and SteriPEN so you can figure out which will be best for you.

Which Should You Choose

When you first look at the LifeStraw and SteriPEN, you may think they’re similar but completely different! The LifeStraw is a water filter, and the SteriPEN is a water purifier.

LifeStraw vs. SteriPEN LifeStraw SteriPEN
Dimensions (W x H x D) 9″ x 1.2″ Dia 7.3″ x 1.6″ x 1.3″
Weight 1.62 oz. 5 oz.
Does it remove Protozoa/Bacteria Yes Yes
Does it remove Viruses No Yes
Filter Type Hollow Filter Membrane UV-C Sterilization
Battery Type N/A Internal
Battery Life N/A 50 Liters of Water
Interface N/A USB
Filter/Lamp Life 1000 Gallons 1000 Gallons


LifeStraw Personal Water Filter for Hiking, Camping, Travel, and Emergency Preparedness, 1 Pack, Blue
  • Removes Bacteria & Parasites: The Microfiltration Membrane Removes 99.999999% Of Waterborne Bacteria...
  • Removes Microplastics: Removes The Smallest Microplastics Found In The Environment (Down To 1...
  • Rigorous Testing: All Claims Are Verified With Laboratories Using Standard Testing Protocols Set By...
  • Long Lifetime: The Microbiological Filter Will Provide 4,000 Liters (1,000 Gallons) Of Clean And...
  • Make An Impact: For Every Lifestraw Product Purchased, A School Child In Need Receives Safe Drinking...

The LifeStraw is the original straw-style water filter designed for hikers, bikers, and other people that enjoy the outdoors. It removes 99.999% of bacteria, parasites, and microplastics.

  • Length: 9″
  • Diameter: 1.2″
  • Weight: 1.62 oz.
  • Filter Life: 1,000 Gallons

Do LifeStraws work?

LifeStraws work exceptionally well. They remove more than 99% of all bacteria and parasites. This means it takes out 99.999999% of waterborne bacteria (this includes e.coli and salmonella) and 99.999% of waterborne parasites (including giardia and cryptosporidium).

It also removes all but the smallest microplastics and sediment.

Can you drink any water with the LifeStraw?

LifeStraws are a filter that removes the sediment, bacteria, and protozoa from the water before you drink it. This means you can grab a gross, dirty glass of water and drink it through the LifeStraw without a problem. LifeStraws don’t filter fuel and other chemicals out of the water, so you need to be sure that there isn’t any chemical contamination in the water you plan to drink.

They also don’t remove viruses. If you suspect that the water has viruses of some kind in it, then you need to go with some other method of getting it clean enough to drink. If this is the case, you can boil the water before drinking it through LifeStraw. This will kill the viruses (as well as the protozoa and bacteria).

It also will not filter out salt from water. So while it may remove the bacteria and parasites from saltwater, you still can’t safely drink it unless you remove the salt some other way.

How many times can you use a LifeStraw?

The long life of the LifeStraw is one of its best-selling points! You can filter about 1,000 gallons of water with one LifeStraw. That’s about five years’ worth of water.

You can read our entire LifeStraw review here.

Do LifeStraws remove viruses?

LifeStraws can’t remove viruses. Viruses are too small to be filtered out by most filters, including the LifeStraw.

How do you clean a LifeStraw filter?

LifeStraws can’t be broken down and cleaned like some other water filters. The best you can do is to blow out the LifeStraw after each use and leave both ends open so the filter can dry out.

You can also suck some clean water into the filter and blow it back out. Of course, you need clean water sitting around for this to work.

When using a LifeStraw, you need to remember that the end that goes into the water can be contaminated. Keep it out of any clean water unless you don’t care that you can contaminate it.

What kind of filter does LifeStraw use?

LifeStraws use a hollow filter microfiltration membrane style filter. Water is forced through the .2 micron pores of the filter as you suck up water.


SteriPEN ULT-MP-EF SterPen Ultra UV Water Purifier
  • UV light destroys germs' ability to reproduce and make you sick; The SteriPEN destroys over 99.9% of...
  • Battery Life: Up to 50 treatments per charge and 300 charge discharge cycles; This is equivalent to...
  • Simple OLED display shows everything you need to know - treatment, lamp, and battery status; USB...

The SteriPEN is a lightweight UV water purifier designed to make water clean and safe for drinking quickly. It eliminates bacteria and protozoa like most water filters but also kills viruses that filters can’t.

  • Weight: 5 oz.
  • Length: 7.3″
  • Width: 1.6″
  • Bulb Life: 1,000 Gallons

Does the SteriPEN work?

The SteriPEN kills 99.9% of all bacteria, protozoa, and viruses. It either flat-out kills or deactivates them, meaning they can’t reproduce or make you sick.

This significant difference is that the SteriPEN doesn’t filter anything out. You’ll deactivate or kill anything in the water, but you’ll still drink it along with any sediment in the water.

One of the best things UV sterilization does (or doesn’t do) does not add any chemicals to your water. If this is important to you, then you’ll like the SteriPEN!

How does UV light kill bacteria?

UV light is a type of radiation. UV-C, the type used to disinfect water, is usually blocked by the ozone, but bulbs like the one in the SteriPEN produce UV-C because it’s so effective in stopping microorganisms.

When these microorganisms are hit by UV light, it damages their DNA and stops them from being able to reproduce. This means that you can’t get sick from them because they need to be able to reproduce to make you sick. By reproducing in your body, they eventually cause adverse health effects.

Can you drink any water with the SteriPEN?

The SteriPEN kills or damages microorganisms. That’s it. This means that you can’t drink chemically contaminated water or water that has salt in it.

How long does a SteriPEN last?

The SteriPEN can disinfect 50 liters of water per charge, and the bulb life lasts for about 8000 activations. One activation disinfects .5 liter, and two activations disinfect 1 liter of water.

What kind of batteries does a SteriPEN use?

This SeriPEN has a rechargeable battery that comes as part of the unit. The USB charging port allows you to recharge the SteriPEN with any USB power packs or solar panels. This makes it great since I usually have a solar panel and battery pack.

You can find other versions of the SteriPEN that use AA batteries if you like batteries that can be replaced better. There are benefits to both, so go with what works for you!

Can you use a SteriPEN in a metal bottle?

SteriPENs can be used in any container you have—glass, metal, plastic, etc. The container blocks any possible harmful UV light that gets produced.

Which is Best for You

Choosing between LifeStraw and SteriPEN can be confusing, but it’s pretty straightforward.

Do you need to treat your water for viruses?

Most of the worst waterborne diseases you will find in North America are caused by bacteria or protozoa. This means that you will probably not need to kill off viruses in your drinking water. The one exception is the possibility of Hepatitis A.

Hepatitis A is spread when human feces from an infected person make it into a water supply. Hepatitis A is found all across the US, but it’s rare for it to be found in water supplies.

If you think you’re likely to come into contact with water contaminated by human waste, then the SteriPEN is what you want.

Most people will be better off with the LifeStraw

Anyone looking for an inexpensive filter that is easy to use and works well in cloudy water should go for the LifeStraw.


The LifeStraw and SteriPEN are two standard pieces of equipment used to make potentially contaminated water sources clean and drinkable.

Both are small and easy to use, but the similarities end there. The LifeStraw is a personal water filter, and the SteriPEN is a UV water sterilizer that can make drinking water for an individual or a group.

In the end, I’d suggest going for the cheaper LifeStraw over the SteriPEN unless you need to treat water for multiple people or you think you’re going to need to treat water for viruses.

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