It’s the closest you can get to a whole-house filtration system, without the expensive costs or the need to disrupt your entire plumbing. Under-sink water filters offer a sleek, seamless solution to point-of-use water treatment, creating space in your kitchen, while also ensuring that your drinking supply is thoroughly filtered before it reaches the faucet.

Here are the best under sink water filters you can buy right now

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Aquasana AQ-5300+.55 3-Stage Max Flow Under Sink Water Filter
  • Instantly Transform Ordinary Tap Water Into Clean, Extraordinary Water - Removes up to 99% of 77 contaminants while leaving healthy minerals so you can drink with confidence. This system will NOT reduce Total Dissolved Solids (TDS).
  • High Flow Rate - This system powers through a half-gallon of water every minute. No need to wait for clean water compared to traditional drip filters.
  • Cost Efficient & Long Lasting - The most economical filter on the market at less than 10 cents per gallon filtered. Lasts for 6 months or 800 gallons before a replacement filter is needed.
  • Easiest Filter Replacement - Replacements are engineered for ease. No need to disconnect hoses or water lines. Eco-friendly housing easily twists off for snappy replacement!
  • Top-Grade Components - Includes first set of filter and all parts required for DIY Installation - No plumber required.
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Frizzlife Under Sink Water Filter System SK99, 3-Stage 0.5 Micron High Precision Removes 99.99% lead, chlorine, chloramine, fluoride - Tankless Quick Change
  • ✔BEST-IN-CLASS FILTRATION PERFORMANCE: Frizzlife 3-stage under counter filter remove over 99.99% of harmful contaminants that are commonly found in water, including LEAD(99%), CHLORINE(99%), CHLORAMINE, FLUORIDE, HEAVY METALS, VOCs and much more. Any unpleasant taste or odor are completely removed, while health-benefiting essential minerals are kept.
  • ✔ECONOMIC & ENVIRONMENT-FRIENDLY: Unlike conventional all-in-one water purification with one-off use, Frizzlife saves your money and contributes to environmental protection through using replaceable filter cartridge M3001/M3002/M3003. Instead of luxuriously disposing of the entire plastic part, you only need to change the inside filter cartridge. Enjoy the superior water filter service in a more economic and green way.
  • ✔DIY INSTALLATION & QUICK CHANGE: Following the clear and straightforward instructions, the filter system can be installed by yourself in a few minutes without the help of a professional plumber. The twist-in filter system makes the filter replacement a breeze. Just use the housing wrench in the box to screw up/down the housing caps to finish replacement effortlessly, no extra tools are required. Your hassle-free life is our concern.
  • ✔FAST WATER FLOW: The flow rate can reach up to 2 GPM. Can always fill up a 330ml cup of water in 3 seconds! Get instant access to safe, pure and tasty water whenever you turn on the tap.
  • ✔GREAT COMPATIBILITY: It is compatible with both 3/8” and 1/2” cold water tube. To ensure our 3/8” hose can perfectly fit with your 1/2” cold water tube as well, extra two 3/8"-to-1/2" converters are provided in case of need.
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Woder WD-S-8K-DC Water Filtration System - WQA Certified – USA Made Ultra High Capacity Direct Connect Under Sink Water Filter - Removes Chlorine, Lead, Chromium 6, Heavy Metals, Odors/Contaminants
  • ULTRA HIGH CAPACITY - LASTS FOR A MINIMUM OF 3 YEARS OR 8,480 GALLONS - Notes: For longest life, use with municipal treated cold water only, not well water. Do not use with salty or softened water. Connects for use only with cold water for drinking.
  • USA MADE - NO PLUMBING REQUIRED – Comes with ‘Direct Connect’ hoses that fit standard 3/8” water valves under US kitchen and bathroom sinks. The 3/8” Direct Connect Hose are made to install directly to the existing cold water valve and faucet stem under your sink. Replacement filters ASIN B0144MFN92.
  • WQA GOLD SEAL CERTIFIED to NSF/ANSI 42 for Chlorine, taste, odor and NSF/ANSI 372 for lead free compliance as verified and substantiated by test data. Flow rate 2GPM @65 psig
  • SELECTIVE FILTRATION - Woder filters have a unique technology that removes over 99.99% of contaminants while leaving in all essential minerals (Reverse osmosis filter out everything, including the minerals your body needs. As far as nutrition goes, experts consider it essentially dead water).
  • PURE AND HEALTHY WATER – WITH NO MORE BOTTLES IN THE FRIDGE - Eliminates lead (99.9%), heavy metals, chlorine (99.9%), chromium 6, mercury, volatile organic compounds, carcinogens, and other contaminants, as well as turbidity, odors and bad tastes, so you and your family enjoy pure, healthy, spring-fresh water from the tap.

What makes under sink water filters different?

Truly on-demand

Thanks to the way they combine with your sink, these filters are sleek and highly versatile. A dedicated filter faucet makes it easy to fill glasses or pots for cooking with one hand. Unlike pitcher filters, most models don’t use a reservoir—meaning there’s no annoying wait for the water to feed through the system. 

A step up in filtering power

Some under sink filters at lower price points use the same filtering mechanism as other kitchen designs. But the majority employ larger, more powerful filtration methods, harnessing mains pressure to push tap water through dense carbon blocks or reverse osmosis membranes (see below). This leaves tap water purer, better tasting, and potentially safer than when using a pitcher or faucet-mounted solution.

Style considerations

Most under-sink models either send water directly through your pre-existing faucet or through a secondary tap, mounted around your sink. Here, many under-sink filters are supplied with their own water dispensers—but you don’t necessarily need to use the dispenser that comes out of the box. Sourcing your own faucet for an under-sink filter can add to the look of your kitchen, making the filter seem more integrated with your other appliances.

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Frizzlife Under Sink Water Filter System-High Capacity Direct Connect Under Counter Drinking Water Filtration System-0.5 Micron Quick Change Removes 99.99% Lead, Chlorine, Bad Taste & Odor.
  • ✔TWO-STAGE ADVANCED WATER PURIFIER WITH 0.5 MICRON: The Frizzlife MK99 Water Filtration System include a TWO-STAGE High precise compoud filter, which has a unique technology that removes over 99.99% of contaminants while leaving in all essential minerals. Eliminates LEAD, HEAVY METALS, CHLORINE, CHROMIUM 6, MERCURY, RUST, VOLATILE ORGANIC COMPOUNDS, CARCINOGENS, AND OTHER CONTAMINANTS, SUCH AS TURBIDITY, ORDORS AND BAD TASTES. Enjoy PURE AND HEALTHY WATER From the tap. NO more bottle water!
  • ✔FITS BOTH 1/2" AND 3/8" COLD WATER LINE: Super EASY Installation. Come with 3/8" DIRECT CONNECT hoses that fits standard 3/8" feed water valves under US kitchen sinks. The Inline water filter system also come with a 3/8" to 1/2" converter fittings allow the system directly install to the existing both 1/2" and 3/8" cold water line and faucet under your sink. Took less than 3 minutes and NO PLUMBING REQUIRED! New installation video available.
  • ✔BEST AUTO SHUT OFF DESIGN: Utilizing quick change twist-in installation design makes it take less than 3 minutes for you to install the system or doing a filter replacement. Provides quick twist connection for easy, tool-free, no mess filter replacement. The filter cap is designed with BUILT-IN shut off valve. You don't even need to shut off the water supply whenever you work on the filter cartridge replacement.
  • ✔HIGH FLOW RATE & MULTI-USAGE: Enjoy tap water as pure and healthy as spring fresh water. Tested Full Flow Rate >2.0GPM @40 psig. Good for cooking, washing fruits & veggies and cleaning dishes without watermarks.
  • ✔MONEY SAVING & 100% SATISFACTION: The under counter water filter system contains a core filter cartridge inside the housing, you will only need to replace the core part of the filter cartridge instead of throwing away the whole plastic part, it will save you much money on replacing the cartridge and will do a lot of helps on the environmental protection. Each cartridge with high capacity can be used for 2 years or 1,600 gallon water, for better filtration, suggest to replace after 6-8 month.
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Culligan US 1 EZ-Change Under-Sink Drinking Water Filtration System with Dedicated Faucet and Filter, 3,000 Gallon, Chrome
  • Provide your family with visibly clean, great-tasting water for drinking, cooking and more
  • FEATURES: Filter reduces particulates class III, chloride and removes bad taste and odor from water; quick connect fittings with twist-on/off function; Includes filter cartridge replacement, tubing, dedicated faucet, and installation hardware
  • COMPATIBILITY: Culligan RC-EZ-1, RC-EZ-3, and RC-EZ-4 replacement cartridges
  • FILTER LIFE: Up to 12 months or 3,000 gallons, depending on usage and water conditions
  • CERTIFICATION: Filter tested and certified by IAPMO to NSF/ANSI Standard 42 for the aesthetic reduction of Chlorine Taste and Odor and Nominal Particulate Class III

How do under sink filters remove contaminants?

Unlike most point-of-use water filters, under sink systems are less constrained by the need to be small or portable. This means they’re able to employ more rigorous, powerful types of filtration mechanisms, such as reverse osmosis and carbon block filters.

Carbon block filters

How do they work?

Almost all water filters you’ll find in a kitchen use some form of activated carbon to remove organic contaminants. But for the most part, only under sink systems employ carbon block filtration. These cartridges are larger than those found in a pitcher or faucet-mounted filter, and are also structured more effectively, in a highly dense matrix that can increase filtration down to less than one micron.

This makes carbon block filters capable of removing super small particles in your water source, from fine sediments, plastics, and rust, to organic matter, which your standard Brita filter is likely to miss.

What do they remove from water?

It depends on a filter’s micron rating, as well as the structure of the matrix—any additional materials added to the activated carbon. However, most activated carbon block filters will remove chlorine, organic chemicals, giardia, cryptosporidium, and other contaminants from your drinking water.

Many models are also infused with aluminum oxide, which makes them capable of removing heavy metals such as lead, mercury, and pharmaceuticals. Always check individual filter products for their filtering ability and NSF international certification.

Reverse Osmosis

How do they work?

A minority of under-sink filters offer reverse osmosis (RO) mechanisms to treat water. 

Reverse osmosis refers to the use of water pressure to push water through semi-permeable membranes, catching tiny contaminants as it passes. Depending on the specific reverse osmosis filter, a membrane can be as fine as 0.0001 microns, which is small enough to filter out almost all common particles and ions.

What do they remove from water?

Most under sink reverse osmosis filters are able to remove all of those potentially harmful contaminants that are often associated with tainted drinking water. These include bacteria, viruses, heavy metals, and some chemical contaminants pesticides.

For the complete guide to RO filtering, including how these devices can even turn seawater into drinking water, read our post on Everything you need to know about reverse osmosis filters [INTERNAL].

Are Under Sink Water Filters Right for You?

Under sink filter pros

  • Seamless filtered water. These filters stake a good claim for being the easiest point-of-use designs available. Not only do they free up space on your kitchen counter, but they don’t require manual filling. Also, their larger size means that cartridge replacements are only necessary every six months, as opposed to around half that for pitcher and faucet filters.

  • Efficient filtering. Unlike most types of kitchen filters, under-sink systems take advantage of the water pressure from your mains system. They use this pressure to push water through the filter, instead of relying on a gravity reservoir. This allows under sink filters to use denser cartridges, which can take on a greater range of pollutants.

Under sink filter cons

  • Installation. Many under sink models can be installed by the homeowner—but there’s also a good chance you’ll need the help of a professional. Be sure to consider any time and costs this may involve. Installation can be less a matter of adapting your under sink plumbing, than making alterations to your countertop. If you have a bespoke counter, alterations may require the services of a stonecutter or carpenter.

  • Kitchen adjustments. On the countertop point, drilling holes in a counter surface may immediately rule out under sink filters for renters and those living in shorter-term accommodation. Reverse Osmosis filters also take up significant cupboard space under the sink, which is hot a huge deal, but worth thinking about.