The Best Faucet Water Filters of 2025

Safe, clean drinking water from our taps is something that many of us take for granted... until we can't. It may be an incident, such as a spill or flood, that impacts your local water supply, or it may be the growing awareness of PFAS and microplastics that affect global water systems. Either way, home water filters installed at the kitchen sink have become increasingly popular, and sadly, sometimes necessary.

There are multiple kinds of home water filters. They may be faucet-mounted or installed under-sink. The filtration system itself varies. You may have heard of activated carbon or reverse osmosis (RO), and wondered which is better. Maybe you just want to improve the taste and smell of your water. Maybe you're contending with a list of scary-sounding contaminants: lead, mercury, bacteria, heavy metals, etc. Whatever the case, this guide is here to help. Our top-rated filter is the AquaTru Under‑Sink RO Purifier, but we’ve got something for everyone. So raise your glasses (of clean water!) and let’s give a toast to water filters.

Things to Consider When Buying a Faucet Water Filter

Before picking a faucet or under-sink water filter, keep the following in mind to ensure you buy the right product for your needs.

Certifications

The gold standard for any water filter is NSF/ANSI certification. It's proof from an independent body that the product actually does what it claims.

Look for filters certified to NSF 42 (for improving taste and chlorine odor), NSF 53 (for removing health-related contaminants like lead), and NSF 401 (for “emerging” contaminants such as pharmaceuticals).

Our top picks have relevant certifications. If a filter isn’t certified, dig into test data or expert reviews before trusting it with something as important as your drinking water.

Installation and compatibility

Consider how the system’s filter installs and whether it fits your kitchen.

Faucet-mounted filters are easiest to install (no tools required in most cases), but check your faucet type—models like Brita or Pur generally fit standard faucets, but not pull-out sprayer types without an adapter.

Under-sink filters require a bit more work: You’ll likely need to attach tubing to your cold water line and drill a hole for the dispenser (unless an existing hole is available, like for a soap dispenser). If you’re handy, this can be a DIY job in under an hour; if not, factor in the cost of a plumber.

Also consider space: Tankless RO systems (Waterdrop) take less room than older RO units with big tanks, but you still need some cabinet space and an electrical outlet.

Contaminant targeting

Not all filters remove everything. It’s important to match the filter to the contaminants you’re concerned about. If your water has a specific issue, such as high lead or chlorine taste, a high-quality carbon filter will cover that. But for issues like fluoride, nitrates, or total dissolved solids (TDS), only a reverse osmosis system will significantly reduce those.

Check your local water quality report or get your water tested to identify any contaminants of concern. The EPA requires that local water suppliers routinely send water quality reports to all customers. They also have this fantastic online resource that allows you to find your own local water Consumer Confidence Reports. Once you know what you’re filtering for, buy the filter that’s rated to remove those substances.

Maintenance (filter life and cost)

Every filter cartridge has a finite life. Once you hit that lifespan limit, you’re not drinking filtered water anymore. Consider how often you’re willing to replace filters and the associated replacement costs. Be honest, are you really going to crawl under sink every few months, or are you just going to ignore it?

Faucet-mounted filters typically last 3 to 4 months (or 100 gallons), while under-sink cartridges can last 6 to 12 months or more (or 500-plus gallons).

Reverse osmosis systems have multiple filters with different lifespans. For instance, Waterdrop’s pre-filter will last for 6 months, but its RO membrane will last for 24 months. All these need replacing on schedule to maintain performance.

Before buying, price out the replacement filters and see if the annual cost is reasonable for you. Some brands offer subscription discounts or multi-pack savings. And don’t forget convenience: Does the unit have an indicator light or app to remind you, or will you need to mark your calendar?

Flow rate and water pressure

When it comes to water filters, there’s a trade-off between filtration thoroughness and flow. Faucet filters usually reduce flow a bit. Under-sink systems often have a separate faucet with decent flow (~0.5 GPM), whereas RO systems can be slower, especially if they use a tankless design that filters on demand.

Stronger flows ensure you’re not waiting long, even for large volumes. But if you have very low incoming water pressure (say, if you live in a high-rise apartment), some systems might output water more slowly than you’re used to. Check if the filter has any pressure requirements.

In general, tank-based filters can deliver a quick burst of water, whereas tankless ROs might take a few extra seconds to fill a glass. Consider your patience level, and if you frequently fill large pots, a high-flow system or non-RO filter might be preferable.

Taste preferences

All these filters will improve the taste of your water by removing chlorine and foul odors. However, reverse osmosis goes a step further and removes nearly all dissolved minerals, resulting in very pure but sometimes “flat-tasting” water (because minerals like calcium and magnesium that give water flavor are gone).

Some people love the ultra-clean taste, others prefer a bit of mineral content. If you want that crisp spring water taste with minerals, you might lean toward a high-quality carbon filter (which leaves minerals in) or an RO system that includes a remineralization stage.

If you prefer the purest taste possible (for brewing coffee or tea, for example, or if you need low-mineral water for appliances), RO is the way to go.

Remember, Brita and similar filters do not significantly change hardness or TDS, so the mouthfeel of the water (and effects on coffee brewing) will differ from RO water.

Environmental impact

One often overlooked factor is the environmental angle. Using any refillable filtering system is far better for the planet than buying bottled water, as just one can replace thousands of plastic bottles per year by cleaning tap water.

That said, consider the waste generated by the filter cartridges themselves. Many brands, like Brita and Aquasana, have recycling programs for used filters, a nice plus if you’re eco-conscious.

Also, note that the RO systems do waste some water by design, but it still means some water goes down the drain during filtration. If you live in a drought-prone area or on a septic system, you might favor a zero-waste filter (like a basic carbon faucet filter, which has no waste stream).

Overall, all these options are more sustainable than single-use bottles, but it’s worth thinking about filter recyclability and water waste in your decision.

By weighing these considerations—certifications, installation, targeted contaminants, maintenance demands, flow rate, taste, and environmental impact—you’ll be well on your way to choosing the best faucet filter for your home. Each of our picks excels in many of these areas, but the right one for you depends on your specific priorities and situation.

Not for Everyone: When a Faucet Filter Isn’t the Right Solution

Faucet and under-sink filters are great for most households, but they’re not one-size-fits-all. Here are a few scenarios where these filters might not be the best fit:

Whole-house filtration needs: If you’re looking to filter water for your entire home (including showers, laundry, etc.), a point-of-use faucet filter won’t cut it. These systems only treat the water at one tap. If you're tackling a widespread water issues (iron staining, hard water scale, sulfur smells throughout the house), you should consider a whole-house filter or softener instead of a faucet filter.

Extremely poor water quality: For water sources with serious contamination (e.g., bacteria from a private well, high concentrations of industrial chemicals, or saltwater intrusion), a simple carbon faucet filter may not be sufficient. For instance, faucet mounts and standard under-sink units are not certified to remove bacteria or viruses; they’re intended for chemically treated municipal water. If biological contamination is a risk (boil-water advisories, well water with E. coli), you’ll need treatments like UV purification, ultrafiltration, or boiling. In these cases, a more robust multi-stage system or reverse osmosis with UV (like the Waterdrop G3) is a safer choice.

If you only want minimal improvement: Some people are perfectly fine with their tap water’s quality but just hate the chlorine taste or want to fill a Brita pitcher less often. If your needs are basic, you might not need a mounted or under-sink filter at all. A cheap water filter pitcher could be enough for better taste. Faucet filters are better for heavy daily use, where the convenience of on-demand filtration matters.

Renters (in some cases): While renters can absolutely use many faucet filters (the Brita doesn’t damage fixtures, and under-sink units can often be installed and removed cleanly), there are situations in rentals that make it tricky. If your landlord doesn’t allow any modifications, even the small hole for an under-sink faucet could be a no-go. And if your kitchen faucet is an unusual type (pull-out sprayer faucets often aren’t compatible with faucet-mounted units), you might need your landlord’s approval to swap fixtures. In such cases, a countertop filter or a filtered water pitcher might be better options that won’t conflict with rental agreements.

Ultra-small kitchens: If you’re extremely tight on space, say, in a tiny apartment or RV, the hardware of a faucet filter or the under-sink real estate for a system like Waterdrop might be problematic. A faucet-mounted filter adds some bulk at the tap, and under-sink units need cabinet space for both the filter and possibly a tank or electric unit. In very small setups, consider compact alternatives like filtered water bottles (which have built-in filters for each drink)—the Grayl is an excellent example that we’ve tested—or a slim pitcher.

FAQ: Faucet Water Filters

Do I really need a faucet water filter if my city water is treated?

Municipal tap water in the U.S. is generally safe to drink from a health perspective, as it must meet EPA standards. However, “safe” doesn’t always mean “tasty” or ideal.

Many cities use chlorine or chloramine to disinfect water, which can leave an odor or off-taste. Older infrastructure can introduce contaminants like lead (from old pipes/solder) into water on the way to your tap, even if the water left the treatment plant clean.

A good faucet filter acts as a final line of defense at the point of use. It can alter the taste by removing chlorine, and provide extra safety by capturing any contaminants picked up en route. Brita and Pur faucet filters, for example, were used in Flint to remove lead effectively.

So while in most circumstances you can could drink straight from the tap, a filter is a relatively cheap upgrade for your palate, and possibly your health. If you suspect anything about your local water, you can usually obtain your city’s water quality report annually, or check the EPA’s website.

What’s the difference between a faucet-mounted filter, an under-sink filter, and a reverse osmosis system?

These are all types of point-of-use water filters (as opposed to a large, whole-house filter), but they operate differently.

A faucet-mounted filter (e.g., Brita Faucet Mount) attaches directly to your existing faucet. It typically uses activated carbon (sometimes with other processes) to remove common contaminants like chlorine, lead, and sediment. They’re cheap and easy to install, but generally have a shorter filter life and cannot remove things like dissolved salts and other things.

An under-sink filter (like the Culligan) sits below your countertop and connects to a separate little faucet. These can incorporate multiple stages (sediment filter, carbon block) to target a wider range of contaminants and often have longer-lasting filters. They’re out of sight and don’t clutter the tap, but installation is a bit more involved, and you have to use the dedicated faucet for filtered water.

A reverse osmosis (RO) system is usually installed under-sink as well. It’s a more complex process that forces water through a semi-permeable membrane. RO can remove tiny impurities that carbon can’t, including arsenic, fluoride, nitrates, and most dissolved solids. It’s the most thorough filtration of the three. However, RO systems produce some wastewater as a byproduct of the process. They’re also pricier. Traditional ROs had bulky storage tanks, but newer ones like the Waterdrop G3 are tankless and use a pump to deliver water on demand.

Do these filters remove lead, PFAS, microplastics, bacteria, viruses, etc?

This is probably the most important question you’re asking. The answer is not simple, as it depends on the filter and the contaminant. Most everyone buying a water filter has one or two top-of-mind contaminants they want out of their drinking water. It’s important to know that no filtration system is 100% effective at removing everything. That’s not the goal. Rather, the goal is to make water safe enough for most people to drink. If you have a specific health concern, like a compromised immune system, talk to your doctor about what’s most important for you to filter out.

Lead: All of our recommended filters remove lead. In fact, this is a key reason to use a filter. There’s no amount of lead that is “good for you”. Look for NSF/ANSI 53 certification for lead. Brita’s faucet filter, for example, is certified to remove 99% of lead, and so is the Culligan Level 4. Reverse osmosis also removes lead effectively.

Chlorine/chloramine: Yes, all our picks reduce the chlorine taste and smell (NSF 42 certification). Chloramine (a chlorine-ammonia disinfectant) is also reduced by carbon filters, though sometimes not as completely. Catalytic carbon is recommended for removing chloramine.

PFAS (forever chemicals): Some advanced carbon block filters and RO membranes can remove PFAS compounds. AquaTru and Waterdrop RO both claim removal of these chemicals as well. Basic faucet filters like Brita are not officially certified for PFAS, though they likely reduce them to some extent. If PFAS is a major concern in your area, an RO system would be a better choice. Certifications are the only way to be sure. Look for products with NSF/ANSI 53 or NSF/ANSI 58.

Microplastics: Surprisingly, many carbon block filters can remove microplastics due to sub-micron pore sizes. Brita hasn’t made strong claims here, but any filtration will catch some microplastic particles. RO, by nature of its membrane, will remove essentially all microplastics as they’re much larger than water molecules.

Fluoride: Fluoride is intentionally added to public drinking water as a health measure. It’s a research-backed, generations-long practice staunchly supported by the American Dental Association, which urges the public to be cautious in the face “pseudo-scientific information” calling for its removal. Faucet and standard under-sink filters do not remove fluoride (they’re not designed to). That said, if you want to remove fluoride, you’ll want an RO system or a specialized filter (alumina-based). Waterdrop RO and AquaTru RO both remove most fluoride from water.

Bacteria and viruses: Generally, carbon filters are not meant for living organisms. They can even become breeding grounds for bacteria if not replaced regularly. If you need biological purification (e.g., untreated well water, or emergency use), you should boil your water or use a filter certified to NSF 55 (UV light, like Waterdrop G3 P800’s UV sterilizer) or NSF P231 for microbial removal. Reverse osmosis membranes can, technically, block bacteria and viruses due to their tiny pore size, but most RO systems are not officially certified as microbiological purifiers unless they have UV or other sanitizing stages. Always start with microbiologically safe water for these filters, or add something like a UV stage if you’re concerned.

Always verify the specific claims of a filter in its performance data sheet. If a particular contaminant is not mentioned, assume that the filter is not rated to remove it effectively.

How often do I need to change the filters, and what happens if I don’t?

The schedule to change filters varies, of course, by product and usage. As a rule of thumb, faucet-mounted filters are changed every 3-4 months, under-sink carbon filters every 6-12 months, and RO membranes every 2 years (with RO pre-filters annually). If you continue using filters past their date, you could experience slowdowns in flow rate and unchecked contaminants making their way into your drinking glass. Check the user manual for precise information. Pro tip: Set a calendar reminder on your phone to change the filter.

Will a water filter reduce my water pressure or flow?

Yes, typically. The difference varies depending on the type of filter, but all of the products in this guide will slow the flow rate to some degree. The water is being forced to squeeze through multiple media, stripping away impurities.

Most people get used to it and can accept the trade-off: cleaner but slower water. However, it can be a problem if your home’s water pressure is low. The water might be unacceptably slow. Conversely, very high pressure can actually push water through filters too fast, potentially reducing contact time. If it’s a concern, you can buy a cheap (under $20) water pressure gauge at any big box home improvement store, then consult with a plumber if your home is outside the normal range.