7 Best Under Sink Water Filters of 2024, Tested by Experts

Oct 20, 2024

This is the secret to cleaner, tastier and healthier tap water.

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Though water in the U.S. is regulated by the EPA (Environmental Protection Agency) to ensure it’s safe to drink and free of contaminants, it’s always better to be safe than sorry, especially since things like lead and chemicals can get into drinking water on its way to your tap. Or if you're on a private well, none of the federal regulations apply. Investing in an under-sink water filter is one of the easiest ways to protect your home’s water from harmful contaminants; the device also filters out chlorine and other disinfectants used by treatment facilities that can give tap water a funny taste and smell.

One major advantage of under-sink water filters: Unlike with standalone water filter pitchers, you’ll save space in your fridge or on your countertop and won't have to constantly keep up with refills (though you will still have to replace filter cartridges every few months). Below, our pros share our favorite top-performing under-sink water filters for your kitchen so you can start enjoying delicious water directly from the tap.

The home improvement experts and test engineers at the Good Housekeeping Institute test everything from water filters to shower filters, kitchen faucets and more. When narrowing down the best under-sink filters for your home from more than 20 reviewed models, we considered whether filters were easy to install (and easy to replace), flow rate, certifications and more. Based on our decades of expertise testing water filters both at home and in the Lab, these are the best under-sink water filters of 2024. After our top picks, continue reading to find out which under-sink water filter is right for your space and how much they cost on average.

Aquasana has staked its reputation as a leader in water filtration over the last quarter century — and the brand has routinely impressed our testers in the process. In fact, we included an Aquasana under-sink filter system in Good Housekeeping's 2023 Kitchen Gear, Coffee & Tea Awards. This 3-stage under-sink filter earns top marks from our engineers, thanks to its innovative multi-filtration technology, which is NSF-certified to capture 77 contaminants, including heavy metals, pesticides, pharmaceuticals and water treatment disinfectants.

It’s also one of the few filters out there certified to remove PFAS, which is a big reason why GH's former Beauty, Health and Sustainability Lab Director, Birnur Aral, Ph.D., put this Aquasana in her own home. As she attests, the device does all that filtering without premature clogging or a drop in flow rate, even though she uses it for everything from cooking to filling the coffee machine each morning. Our pros note that it's easy to install, however it may take up more cabinet space than others. The filter-replacement cost with this unit is also more than most (averaging around $140/year), so it's more expensive to operate throughout the year.

While we haven’t tested this system yet in the Lab, Culligan is another trusted name in water filtration with a well-established record from past Good Housekeeping Institute reviews. Besides its low initial cost, replacement filters are relatively affordable at around $80 per year. The system is certified to capture a wide range of contaminants, including lead, mercury and cysts, and it claims to reduce chlorine taste and odor.

That said, its granular activated carbon filtration is not quite as robust as other top picks: For example, the filter is not certified to NSF standard 401, which covers pharmaceuticals, herbicides and pesticides. The EZ-Change can filter 500 gallons before needing a replacement. That’s respectable for a bargain-priced filter, but less than the 700 to 800 gallons we see with other models, so the Culligan is better suited to small households.

Our engineers found that Waterdrop's tankless design saves space compared with traditional reverse osmosis (RO) systems and is more efficient too. While we haven’t run extensive home tests, past reports on RO technology support its efficacy at capturing contaminants.

The Waterdrop is NSF 58 certified, one of the highest standards, so it can stand up to everything from heavy metals to pharmaceuticals to PFAS. Our pros like the device’s intelligent design, including the filter light indicator on the faucet and the smart monitoring panel, which tells you the quantity of TDS, or total dissolved solids, being filtered out of your water. One caveat: Unlike other filters in this round-up, the Waterdrop is not intended for well water, since the presence of large particulates can cause clogging.

If cabinet storage space is tight in your kitchen, you’ll appreciate the compact design of Multipure’s under-sink water filter. In extensive home tests, our experts noted that the 5.8" x 5.8" x 8.5" housing can be mounted to a cabinet wall, leaving plenty of room for other items under the sink.

Initial installation was straightforward according to our experts, and it’s easy to replace the filter. Certified to NSF standards 42, 53 and 401, the solid carbon block filter (versus granulated carbon) is excellent at capturing a wide range of contaminants. Our tester reported that, provided the filter is changed annually, flow rate remains strong and steady even during the summer months, when household water consumption peaks. It also resists clogging. However, the dispenser isn't quite as sturdy as those we've evaluated on other models.

The Brondell under-sink water filter costs less than many reverse osmosis (RO) systems. According to our pros, it's easy to set up and simple to swap filters in and out. It's also safe for well water, and extremely compact for an RO system. As for performance, our engineers note that the system is certified under NSF/ANSI Standards 42, 53, 58 and 372. That means it delivers crisp-tasting water, without any chlorine odors, while protecting against the vast majority of contaminants, including known concerns, like lead and pesticides, as well as emerging ones, like pharmaceuticals in the water supply.

The certification also ensures the structural integrity of the system, so you won't have to worry about parts failing prematurely. Though the Brondell does waste some water in its filtering process, it is 10 times more efficient than traditional RO systems, according to the brand.

This 2023 Kitchen Gear Award Winner stood out to our Lab experts and testers for its easy installation and convenience. Unlike other filters we tested, it hooks up directly to your existing faucet, making it an excellent choice for apartments or rentals where installing a separate dispenser (which usually involves drilling into the sink deck) isn't advised.

The Aquasana only connects to your cold water line so hot water won't be filtered or wasted while cleaning dishes. "Still, you end up treating a lot more water compared with systems that use a side dispenser intended mainly for drinking water," says Dan DiClerico, director of the Home Improvement & Outdoor Lab at the Good Housekeeping Institute. "That means you'll need to replace filters more frequently, adding to the total operating cost." Testers found it handy for filling up coffee pots and other large containers. We also like that it's certified by NSF Standards 42, 53 and 401, meaning it will effectively remove contaminants like chlorine, lead, pharmaceuticals and more.

This under-sink water filter is the perfect combination of performance and price, according to DiClerico, and ideal for a two- to three-person household. The brand claims that the 2-stage filtration system will effectively remove up to 78 common contaminants, including chlorine, lead, pesticides, PFOS, microplastics and more. In Lab tests, our experts found the filter easy to install and the replacement filter fairly affordable (around $140 per year). It's best suited for soft water, so city dwellers may need to opt for another under-sink water filter to help remove excess minerals.

To narrow the list of contenders for this guide, our experts considered only water filters certified by NSF International, the organization that develops public health standards and certification programs for the industry.

Over the last five years, we have reviewed scores of data points from about 20 under-sink water filters. Our experts pay particularly close attention to which NSF standard the filters are certified for (some standards cover only lead, like NSF 372, while others also include agricultural and industrial toxins, like NSF 401).

As part of our hands-on tests, our Lab experts looked at factors such as flow rate and how easy it is to install and replace the filter. We also took into consideration a brand’s track record and reliability, drawing on decades of water filter testing in our homes and Labs.

Under-sink water filters are also known as point-of-use filters, since they treat only water coming from a single source, typically the kitchen faucet. The basic mechanics are always the same, but there are a couple of variables to consider.

✔️ Filtration: There are several different types of filters, depending on your needs. If you get your water from your city, you should receive an annual Consumer Confidence Report (CCR) telling you what contaminants were detected in your municipal water supply in the past year. It's also a good idea to test your water regularly. DIY kits, available online and at home centers, are affordable and easy to use. These are the main kinds of filters:

✔️ Installation: While every system is unique, most come with a filter housing that gets mounted to an inside wall of your sink cabinet. Always check the dimensions listed in our product reviews (or on the manufacturer's website) to ensure there's room in your cabinet. One end of the filter ties into your cold-water line via a flexible connection. A second connection goes from the other end of the filter to the dispenser, which sits on your sink deck. Installing the dispenser is often the trickiest part, since it involves drilling a hole in the countertop. Capable DIYers should be able to handle the project, but it might be worth calling in a plumber if you’re less experienced, especially if your water line needs to be modified.

✔️ Maintenance: The main consideration is filter replacement and filter capacity. Take note of the steps and costs that go into the process. Our pros look for models with long-lasting filters and high filter capacity (400 gallons is good, 600-plus gallons even better), affordable replacement filters ($100 or less, per year) and simple "tool-free" swapping in and out of the filters.

✔️Flow rate: The flow rate refers to how much water can flow through a filter within a given amount of time. It's usually measured by gallons per minute (GPM). The higher the flow rate, the better your water pressure will be.

Given the array of contaminants, including lead, arsenic and PFAS, that can find their way into drinking water supplies, it’s absolutely worth investing in an under-sink water filter for your home, explains Dan DiClerico, the Good Housekeeping Institute's Home Improvement & Outdoor Lab Director. It's one of the easiest ways to ensure you're only getting the best-tasting and healthiest water in your home. "Even if your tap water is free of toxins, the addition of chlorine at the water treatment facility can give it a funny taste and smell that a good under-sink filter will eliminate," DiClerico says.

According to our pros, you can spend as little as $100 on an under sink water filter or as much as $500. "More expensive filters tend to have more robust filtration systems," explains DiClerico. He advises shoppers to also pay attention to the replacement filter costs, which can range from $100 to $200 a year.

Water filters that work by reverse osmosis remove the most contaminants, says DiClerico. "The downside is they waste water in the filtration process, though they are becoming more efficient as manufacturers improve the technology," he adds.

Dan DiClerico has written about the residential water filter market for more than 20 years, reviewing dozens of models from every leading brand. He also keeps up with the latest innovations by attending trade shows and industry events, like CES and the Kitchen and Bath Industry Show. In his role as director of the Home Improvement & Outdoor Lab at the Good Housekeeping Institute, Dan oversees water filter testing alongside our health and technical experts.

This guide was updated by writer and product analyst Olivia Lipski, who covers everything from consumer electronics to home, outdoor, fitness and more. She consulted with DiClerico and the Lab’s extensive testing data when updating the picks featured above.

Olivia (she/her) is a senior reviews writer and analyst at the Good Housekeeping Institute, overseeing product testing and covering tech, travel, home, fitness, parenting, health and more. Since joining GH in 2021, she has continued to leverage her extensive product reviews experience by staying on top of the industry’s latest innovations and helping readers make better buying decisions. Olivia is a graduate of the George Washington University, with a bachelor’s degree in journalism, political science and French, and she holds a master’s degree in communications from Sciences Po Paris.

Having written thousands of product reviews and how-to articles on all aspects of home ownership, from routine maintenance to major renovations, Dan (he/him) brings more than 20 years of industry experience to his role as the director of the Home Improvement & Outdoor Lab at the Good Housekeeping Institute. A one-time roofer and a serial remodeler, Dan can often be found keeping house at his restored Brooklyn brownstone, where he lives with his wife and kids.

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