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5 Best Inline Water Filter(Review & Guide)

Scott Winfield
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by Scott Winfield

The name “inline filters” comes from the fact that these water filtration units are installed directly in your water line.

They’re incredibly compact cylindrical cartridges attached along the water line leading to your faucet or any home appliances requiring clean water, like refrigerators or coffee makers.

Inline water filters are effortless to install, take up virtually no space, and are incredibly cheap.  All these qualities make them very popular among homeowners, so there are plenty of models on the market for you to pick from.

If you’re overwhelmed by the sheer number of options, our article will help you choose the best inline water filter for your needs.

Best Inline Water Filter

  1. LASCO 37-1821 Inline Water Filter – Best All-Rounder
  2. Clearly Filtered Universal Inline Filter – Most Contaminants Removed
  3. Watts Premier Inline Water Filter – Best Filter Life
  4. Woder WD-10K-JG Inline Water Filter – Best Flow Rate
  5. Epic Smart Shield Universal Inline Filter – Most Effective Filter

LASCO 37-1821 Inline Water Filter – Best All-Rounder

LASCO 37-1821 Inline Water Filter
  • Contaminants: Chlorine, sediment, THMs, unpleasant tastes and smells
  • Filter Life: 2,500 gallons
  • Flow Rate: 0.50 GPM
  • Price: $34.82
  • 30-day money-back guarantee
  • Very affordable
  • Decent filter life
  • Limited flow rate

The LASCO 37-1821 is the inline filter of choice for anyone who wants to cover all their bases.

This inline filter can remove chlorine, sediment, unpleasant tastes, and odors. This makes the LASCO an excellent option if your priority is eliminating the most common contaminants in water.

Moreover, it won’t break the bank. The unit is an absolute bargain, coming at just $34.82. The price becomes even more attractive when you consider that the filter can purify 2,500 gallons before you need to get it replaced. For context, the 2,500-gallon capacity equals around six months of use.

Then, there’s the fact it’s convenient to place. LASCO 37-1821 may be mounted horizontally and vertically, easily fitting on any 1/4-inch line.

Additionally, if you have any issues with installing this unit on your water line or fitting it behind your refrigerator, you’ll be happy to know there’s a 30-day return policy you can use to return it or replace it.

The weakest feature of this inline filter is the flow rate. Inline filters usually have a flow rate of 0.50 to 0.75 GPM, except the Woder WD-10K-JG, which has a flow rate of 3 GPM. LASCO’s 0.50 GPM is on the lower end, which adds to its filtration time.

However, this unit is a great fit for any home, even with the limited flow rate. It removes the most common contaminants from your water supply, it’s incredibly cheap, and the filter life is impressive. The extra few seconds you’ll have to wait for the water to get purified are insignificant, considering all of this unit’s benefits.

Clearly Filtered Universal Inline Filter – Most Contaminants Removed

Clearly Filtered Universal Inline Filter
  • Contaminants: 232+ contaminants, including heavy metals, pollutants, and chemicals.
  • Filter Life: 365 gallons
  • Flow Rate: 0.75 GPM
  • Price: $165
  • Three-stage filtration process
  • 30-day money-back guarantee
  • Comes with a limited lifetime warranty
  • One of the most expensive inline filters on the market

The Clearly Filtered Universal Inline Filter is the most impressive system on our list in terms of contaminant removal capacity. This unit helps you eliminate a staggering 232+ contaminants from your water. This number is significantly larger than most of the other units on our list, thanks to the three-stage filtration process the unit employs.

The first stage is the porous activated carbon media that absorbs chlorine, chloramine, herbicides, and pesticides, as well as bad tastes and odors.

The second stage is the specialized heavy metal media that remove microplastics, pharmaceuticals, and, you guessed it – heavy metals.

The third and final stage is a fluoride media that stays true to its name since it removes fluoride and arsenic from your water.

This filtration process is very effective and removes approximately 99% of lead and PFOA/PFAS, 90% of fluoride, and 98-99% of all other common water contaminants.

The Clearly Filtered Universal Inline Filter also comes with a few quality-of-life perks, like the free shipping option throughout the US. You also have a 30-day money-back guarantee to return the filter if you have a problem with it.

Additionally, this item also comes with a limited lifetime warranty and long filter life. If you use it for your sink, the filter life should last 1-3 months, depending on your water usage. However, if you use it for your refrigerator, you’ll get up to two years of use before the filter exceeds its 365-gallon limit.

That being said, its high efficiency is reflected in the price, as this is the most expensive inline filter on our list. We recommend it for households where the water is heavily contaminated.

Watts Premier Inline Water Filter – Best Filter Life

Watts Premier Inline Water Filter
  • Contaminants: Chlorine and heavy metals
  • Filter Life: 20,000 gallons
  • Flow Rate: 0.75 GPM
  • Price: $16.49
  • The filter can last you for as long as five years
  • One of the most affordable inline filters on the market
  • Decent flow rate
  • Only capable of removing two contaminants

Watts is the inline water filter of choice for anyone that wants a versatile and durable purification system. According to the manufacturer, its unbelievable filter life of 20,000 gallons is more than enough to last most people around five years.

Of course, estimating the exact time is not possible, as it depends on individual water usage. However, even if you manage to get four years of use out of this inline filter, we believe that’s a pretty good deal for an item costing $16.49.

Watts Premier uses kinetic degradation fluxion to eliminate chlorine and heavy metals from your water. The flow rate is 0.75 GPM, so it can filter the water faster than the LASCO 37-1821 and the Epic Smart Shield models, although it falls behind the Woder WD-10K-JG’s flow rate of 3 GPM.

The big flaw of this system is that it only filters chlorine and heavy metals, meaning it’s practically useless for other common water contaminants. In addition, the filter can’t even absorb tastes or smells like most other filters utilizing carbon media on our list.

Speaking of the other filters, all of them eliminate chlorine and heavy metals, so you’ve got plenty of other choices to pick from if your water holds either of these pollutants.

However, having said all that, the incredibly low price and long filter life make this unit the best option for anyone who wants to remove particular contaminants at practically no cost.

Woder WD-10K-JG Inline Water Filter – Best Flow Rate

Woder WD-10K-JG Inline Water Filter
  • Contaminants: Lead, heavy metals, chlorine, mercury, and ten more.
  • Filter Life: 10,000 gallons
  • Flow Rate: 3 GPM
  • Price: $48
  • Outstanding flow rate for an inline filter
  • Excellent filter life
  • 1-year warranty
  • The 12″ X 2.52″ X 2.52″ dimensions make this filter cumbersome to place behind a fridge

As we’ve alluded to several times throughout the article, not only does the Woder WD-10k-JG have the best flow rate compared to the other products on our list, but it also has one of the best flow rates for an inline filter in general.

Additionally, this unit features a very long filter life as well. While it may be eclipsed by the 20,000-gallon filter life of the Watts Premier Inline Water Filter, the Woder can still filter 10,000 gallons of water before replacing it. According to the manufacturer, this is more than enough to last most people for around three years.

As always, the exact lifetime of the filter will be shortened or extended depending on the amount of water used regularly. However, even if you somehow manage to use so much water that you reduce the filter life to a single year, that’s still a good deal, all things considered.

This low price seems particularly appealing when you take into account that the filter can remove more than 12 different types of contaminants. These contaminants include chlorine, lead, mercury, heavy metals, bad tastes and odors, and more.

You also get a one-year warranty, which is more than decent for a device in this price range.

Another strength of this unit is that it can be attached to both 1/4 and 1/8-inch lines, giving it a bit more versatility when it comes to the types of appliances and sinks for which it’s suitable.

One thing to keep in mind about this unit is that it’s 12 inches long and 2.5 inches wide, making it a bit larger than the other filters, as most are around 10 inches in length and 2 inches in width.

Epic Smart Shield Universal Inline Filter – Most Effective Filter

Epic Smart Shield Universal Inline Filter
  • Contaminants: 116
  • Filter Life: 365gallons
  • Flow Rate: 0.50 GPM
  • Price: $62
  • Powerful two-stage filtration system
  • Reasonably priced
  • Removes 99% of most common water contaminants
  • Limited filter life

While other filters like the Clearly Filtered Universal Inline Filter remove many more types of contaminants, the filtration process that this unit uses is much more effective than most other filtration methods employed by inline units.

While other inline filters only use a single-stage filtration process (except for the three-stage Clearly Filtered Inline Filter), the Epic Smart Shield Universal Inline Filter has a two-stage process that passes the water through a hollow fiber membrane and an activated carbon block filter.

The carbon block filter eliminates chlorine, heavy metals, and various chemicals, as well as unpleasant tastes and odors from the water. In terms of removal capacity, the filtration process can get rid of 96% of chlorine, 99% of copper and uranium, and 98% of PFOAs, mercury, and lead from your water.

The hollow fiber membrane then takes care of microorganisms like cysts, viruses, and bacteria. While no exact numbers are given when it comes to removing these contaminants, the manufacturer claims the filter is effective against 99% of the most common water contaminants. If this is true, the filter will also remove most viruses and bacteria.

Unfortunately, the one downside of the highly effective filtration process is its limited life. The 365-gallon filter life can last for around two or three months if you’re conservative with your water usage. However, you might reduce the filter life to roughly a month if you use it regularly.

Therefore, we recommend this filter for anyone living in an area with polluted water who doesn’t have room for a whole-house filtration system.

Alternatively, if you use this filter for your refrigerator only, you’re likely getting a few years out of it before you need to replace it. However, keep in mind that the same is true for most other inline filters.

How Does an Inline Water Filter Work?

An inline water filter is a cylinder or a cartridge with filter media inside. The filter has an input point on one end and an output point on the other. Once both sides are connected to the water line in your house, all you need to do is turn on the water.

The water is propelled through the filter media inside the cartridge, where contaminants are neutralized or removed.

Unlike other filters, these filter cartridges don’t need a separate appliance like an RO system to purify the water that passes through them. Once the filter’s life has expired, all you need to do to replace it is throw away the current cartridge and add a new one.

Advantages of Inline Water Filters

Inline filters are incredibly small, so they can be installed anywhere without taking up any space. Their small size is thanks to the fact the filter cartridge is the filter itself — you don’t need to attach the cartridge to a large filtration unit, which saves you space.

On the one hand, these filters don’t have replaceable cartridges and must be thrown away once they expire. But on the other hand, they cost about as much as a standard reverse osmosis system cartridge anyway, so you’re not losing money by replacing the units.

The installation itself may be tricky if you’re not good with tools, but the process itself is not too complicated.

Connect one end of the water line to the input hole on the inline filter, and connect the other part to the output hole. You should be able to attach everything with a little trial and error in about 10 minutes.

Inline filters are also pretty durable. Most filters can only filter a few hundred gallons of water, equal to 2 or 3 months of use, but some inline filters have a life of a year or more.

Disadvantages of Inline Water Filters

Due to their size, inline water filters are mostly single-stage filtration units, which makes them capable of reducing the contaminants in your water to a certain point. However, most aren’t able to handle highly polluted water.

Inline filters are best used with city water that’s already been filtered but still might contain some contaminants. Even the units filtering multiple pollutants will get clogged and won’t be able to remove those same contaminants if the contaminant concentration is too high.

Determining water pollution is another problem. Inline filters don’t have filter life indicator lights or strips like other filtration units, so the only way to determine whether a filter needs to be replaced is to keep an estimate of the amount of water you’ve used.

Alternatively, you may send a water sample to a testing lab or get a home testing kit if you think your water tastes and smells funny. This is the only way to find out if an inline filter can handle the pollutants or if it got blocked up and isn’t working correctly.

The same applies to the filter life. Even if the water is relatively clean and the filter is working as intended, you can’t see when the filter needs to be replaced other than to test the water or manually keep track of your water usage.

Frequently Asked Questions

Let’s answer some of the most common questions regarding inline filters.

What is the cheapest inline water filter?

The cheapest inline water filter on our list is the Watts Premier Filter. Even if you look online for a filter more affordable than $16.49, it’s doubtful that you’ll find a match for Watt’s filter life.

What is the average price of an inline water filter?

Inline filters have a general price range of $30 to $60, with the exact price varying depending on their contaminant removal capacity, filter life, and several other factors.

What does installing an inline water filter require?

All you need to do to install an inline water filter is to screw it onto a water line in your home. Then, turn off the water leading to the spot where you’ll be attaching the filter, remove the hose from the sink or the appliance, screw the hose on the filter, and screw the filter into the appliance or sink.
Once everything is in place, turn the water on to ensure there are no leaks, and you’re good to go.


The LASCO 37-1821 Inline Water Filter is reasonably priced, has a good filter life, and can remove some of the most common water contaminants, making it an ideal choice for many homes.

The Clearly Filtered Universal Inline Filter is able to destroy over 300 water contaminants, making it an ideal option for anyone with many different types of pollutants in their water.

The Watts Premier Inline Water Filter is the best choice for anyone that wants to get as much bang for their buck as possible since this unit should last for five years.

The Woder WD-10K-JG Inline Water Filter has the best flow rate out of all the units we recommend, so it’s a good option for anyone that wants the filtration process to finish as quickly as possible.

The Epic Smart Shield Universal Inline Filter removes 99% of the contaminants that pass through the filter media, making it a good choice for people that live in polluted areas.

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Scott Winfield
Scott Winfield
My name is Scott Winfield and researching and writing about water filters and other strategies to purify water has become my full time passion in recent years. I'm glad that you found our site and you can look forward to authoritative and well researched content here to help you get the best in water.
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