Best Reverse Osmosis Under-sink Filters of 2026

Jennifer Fraser Avatar
Jennifer Fraser
Last Updated: 4 Feb 2026

* We independently evaluate all recommended products and services. If you click on links we provide, we may receive compensation.

Reverse osmosis under-sink filters are a popular choice for households looking to improve the taste and quality of their drinking water. These filters use a semi-permeable membrane to remove impurities from water, including bacteria, viruses, and chemicals. The result is clean, fresh-tasting water that is free from contaminants. Reverse osmosis filters are easy to install and maintain, and they are an effective way to ensure that your family has access to safe, great-tasting water at all times.

At a Glance: Our Top Picks

Finerfilters 5 Stage Reverse Osmosis Water Filter Cover #TOP 1
Finerfilters 5 Stage Reverse Osmosis Water Filter
ftb score rating icon 9.9
Finerfilters 6 Stage Reverse Osmosis Water Filter System Cover #TOP 2
Finerfilters 6 Stage Reverse Osmosis Water Filter System
ftb score rating icon 9.8
Geekpure 6-Stage Reverse Osmosis Water Filter System Cover #TOP 3
Geekpure 6-Stage Reverse Osmosis Water Filter System
ftb score rating icon 9.6

Top 10 Reverse Osmosis Under-sink Filters

#TOP 1

Finerfilters 5 Stage Reverse Osmosis Water Filter

FF-RO-SYST-D5
white
Finerfilters 5 Stage Reverse Osmosis Water Filter Cover
Finerfilters Reverse Osmosis Under Sink Drinking Water Filter System (50GPD) for Home Domestic, Removes up to 99% of Contaminants for the Very Best Drinking Water (5 Stage)

The Finerfilters RO Water Filter ensures you enjoy the best drinking water straight from the tap. With its advanced 5-stage filtration system, it removes up to 99% of contaminants, including harmful substances like lead and chlorine, giving you cleaner, safer water. You’ll appreciate the improved taste in your teas, coffees, and juices, as well as the crystal-clear ice cubes it produces. Capable of generating up to 190 litres of purified water daily, this system provides convenience for all your hydration needs.

What We Like
Removes up to 99% contaminants
Produces 190 litres daily
Improves taste of beverages
Includes easy installation kit
Compact under-sink design
#TOP 2

Finerfilters 6 Stage Reverse Osmosis Water Filter System

FF-RO-SYST-D6-PUMP
white,blue
Finerfilters 6 Stage Reverse Osmosis Water Filter System Cover
Finerfilters 6 Stage Reverse Osmosis Water Filter System with Booster Pump (50GPD) for Under Sink Home Domestic, Removes up to 99% of Contaminants and Remineralises to Replenish Essential Minerals

The Finerfilters RO Water Filter delivers exceptional drinking water quality. With its advanced filtration system, it effectively removes up to 99% of contaminants, ensuring you enjoy cleaner, safer water right from your tap. This system also includes a remineralisation feature, enriching your water with essential minerals for better taste and health. Furthermore, it can produce an impressive 190 litres of purified water daily, making it perfect for all your household needs. You’ll find it convenient for brewing tastier beverages and preparing cleaner meals.

What We Like
Removes up to 99% of contaminants
Produces 190 litres per day
Includes remineralisation feature
Easy DIY installation
Chrome faucet included
#TOP 3

Geekpure 6-Stage Reverse Osmosis Water Filter System

RO6-DI
White
6 Stage (DI)
Geekpure 6-Stage Reverse Osmosis Water Filter System Cover
Geekpure 6 Stage Reverse Osmosis Drinking Water Filter System with DI Filter TDS to 0-75 GPD

The Geekpure RO Water Filter offers a 6-stage reverse osmosis system that removes harmful substances like arsenic, lead, fluoride, and mercury, giving you cleaner and healthier drinking water. It features a special deionization filter that further reduces total dissolved solids, ensuring your water tastes fresh and pure. The system uses NSF-certified components, including quick push fittings and a reliable membrane, so you can trust the water quality. With a capacity of 75 gallons per day and a compact tank, it fits neatly under most sinks, providing you with great-tasting water anytime.

What We Like
Removes harmful contaminants effectively
Includes deionization for pure water
NSF-certified components for safety
Compact size fits under sink
Easy DIY installation kit
#TOP 4

Geekpure 6-Stage Reverse Osmosis Water Filter System

RO6-AF
White
75GPD
Geekpure 6-Stage Reverse Osmosis Water Filter System Cover
Geekpure 6-Stage Reverse Osmosis Drinking Water Filter System with Alkaline pH+ Remineralization Filter-75 GPD

The Geekpure Water Filter System offers a comprehensive 6-stage reverse osmosis filtration process, ensuring that harmful contaminants like arsenic, lead, and fluoride are effectively reduced. You will enjoy fresher, healthier water that enhances the taste of your beverages and foods, making even your ice cubes clearer and tastier. An added alkaline remineralisation filter adjusts the pH of your water to a balanced level, restoring essential minerals for improved taste. With easy DIY installation and high-quality components, this system simplifies the process of obtaining pure water right at your sink.

What We Like
Removes harmful contaminants
Improves taste of water
Restores essential minerals
Easy DIY installation
#TOP 5

iSpring RO400 Tankless Reverse Osmosis System

RO400
White
400 GPD
iSpring RO400 Tankless Reverse Osmosis System Cover
iSpring RO400 Reverse Osmosis System, Tankless Water Filtration System, 400 GPD Fast Flow Under Sink RO System with Brushed Nickel Faucet, 2.5:1 Pure to Drain Ratio, TDS Reduction, White

The iSpring RO400 is an advanced tankless reverse osmosis system that delivers up to 400 gallons per day with a remarkable 2.5:1 pure to wastewater ratio, making it highly efficient. It features a 4-in-1 PCT filter that removes over 99% of harmful contaminants, ensuring you have access to clean, safe drinking water. The built-in filter life indicator alerts you when it’s time for a replacement, helping you maintain optimal performance. Additionally, its compact, easy-to-install design saves valuable space under your sink.

What We Like
Highly efficient water usage
Removes 99% of contaminants
Filter life indicator
Easy installation
Space-saving design

iSpring RCC7AK-UV 7 Stage Water Filtration System

RCC7AK-UV
RCC7AK-UV
iSpring RCC7AK-UV 7 Stage Water Filtration System Cover
iSpring RCC7AK-UV 7 Stage Under Sink Reverse Osmosis Drinking Water Filtration System with Alkaline Remineralization Filter and UV Sterilizer, 75 GPD

The iSpring RCC7AK-UV System features a robust 7-stage filtration process that can eliminate up to 99% of over 1,000 contaminants, ensuring your drinking water is safe and clean. With its advanced UV lamp, this system is particularly effective for dealing with unreliable water sources, such as well water or lakes. The Alkaline Remineralization filter restores beneficial minerals and improves the water's natural taste. Made from high-quality materials, the system promises reliability and low maintenance for years to come.

What We Like
Removes 99% of contaminants
Effective UV sterilisation
Restores healthy minerals
Durable and low maintenance
#TOP 7

Frizzlife PD600 Tankless RO Water Filter

400 GPD RO
white
Frizzlife PD600 Tankless RO Water Filter Cover
Frizzlife Reverse Osmosis System - Tankless 400 GPD Drinking Water Filtration System, Quick Twist Under Sink RO Filter - 1.5 : 1 Pure to Drain - Reduce TDS, Compact Footprint, USA Tech Support, PD400

The Frizzlife PD600 Filter provides an exceptional drinking water experience with its advanced features. The remineralisation and alkalisation stage ensures your water is not only safe but also health-enhancing by balancing pH levels. With a remarkable capacity of 600 gallons per day, you can enjoy a steady flow of fresh water, filling a cup in just 10 seconds. The efficient 1:1.5 low drain to pure ratio means you save water and reduce bills, making it both economical and environmentally friendly. Plus, the smart LED display keeps you informed about filter status easily.

What We Like
High-capacity water flow
Water-saving technology
Remineralises and alkalises water
Compact tankless design
Easy installation with clear display
#TOP 8

iSpring RCC1UP-AK 7-Stage RO System

RCC1UP-AK
White
iSpring RCC1UP-AK 7-Stage RO System Cover
iSpring RCC1UP-AK, 100 GPD 7-Stage Reverse Osmosis Under Sink Water Filtration System with Boost Pump, Alkaline Remineralization and UV Filter, Patented Top-Mounted Faucet Design for Easy Installation

The iSpring RCC1UP-AK is a comprehensive under-sink filtration system that promises exceptional water quality. With its 7-stage filtration, it effectively removes up to 99% of harmful contaminants, ensuring you enjoy clean and safe drinking water. The booster pump boosts water pressure, delivering higher throughput and minimising waste, which is perfect for those concerned about efficiency. Additionally, the UV filter stage automatically activates with water flow, saving energy and extending the UV lamp's lifespan, making it a smart choice for eco-conscious users.

What We Like
High contaminant removal rate
Efficient booster pump
Automatic UV filter activation
Easy DIY installation
Durable and low maintenance
#TOP 9

Waterdrop KJ600 Instant Hot Water RO System

WD-K6
White
Waterdrop KJ600 Instant Hot Water RO System Cover
Waterdrop Reverse Osmosis Instant Hot Water RO Filter System, 600 GPD, 2271L, Tankless, 2:1 Pure to Drain, Under Sink, TDS Reduction, Smart LED Faucet, WD-KJ600/WD-K6

The Waterdrop KJ600 RO System provides instant hot water, allowing you to adjust the temperature between 40-95°C for various tasks like cooking and making beverages. With its advanced 5-stage deep filtration, it effectively reduces harmful substances such as TDS, heavy metals, and fluoride, ensuring you enjoy clean water. The high-end smart display faucet offers easy access to TDS levels and filter conditions, enhancing your experience while ensuring safety with features like a child lock. The tankless design delivers hot water quickly, making it a convenient addition to your kitchen.

What We Like
Instant hot water dispensing
Effective 5-stage filtration
Smart display for easy monitoring
Quick and efficient water flow
Customisable temperature settings
#TOP 10

AQUAPHOR RO-101S Compact Reverse Osmosis System

101S
R0-101S
AQUAPHOR RO-101S Compact Reverse Osmosis System Cover
AQUAPHOR RO-101S Compact Reverse Osmosis Water Filter - Under Sink Filtration System

The AQUAPHOR RO-101S is an innovative under-sink reverse osmosis water filter that purifies your tap water, ensuring you have clean and great-tasting water for drinking and cooking. Its unique water-on-water tank design saves space and reduces water wastage, making it eco-friendly. With the ability to operate at low water pressure, you can enjoy pure water even in homes with less than ideal conditions. This system also effectively removes hardness from water, prolonging the life of your appliances like coffee machines and kettles.

What We Like
Space-saving design
Reduces water wastage
Improves appliance lifespan
Perfect for baby food
Great tasting water
Buying Guide Image

Frequently Asked Questions (FAQs)

1. Why should you not drink reverse osmosis water?

RO water which doesn't contain enough minerals, when consumed, leaches minerals from the body. This means that the minerals being consumed in food and vitamins are being urinated away. Less minerals consumed plus more minerals being excreted causes serious negative side effects and big health problems.

2. Can RO be installed under sink?

As the name suggests, an under-the-sink RO water purifier is your best bet when you have a lack of space to install a water purifier in the kitchen. These water filters can be easily tucked in your kitchen to save space and avoid making any changes to the kitchen.

3. How effective is reverse osmosis water filter?

Reverse osmosis, also known as RO, is a type of water filtration that can reduce up to 99% of the contaminants in water, including both larger particles and those that can't be seen. * This is typically a multistage process that includes pushing the water through a specialized, semipermeable membrane.

4. What Cannot be filtered by reverse osmosis?

Reverse osmosis units do not effectively remove most organic compounds, bacterial microorganisms, chlorine by-products, or dissolved gases like carbon dioxide, methane, and radon.

Editor's Notes

During our reverse osmosis under-sink filter research, we found 263 reverse osmosis under-sink filter products and shortlisted 10 quality products. We collected and analyzed 31,748 customer reviews through our big data system to write the reverse osmosis under-sink filters list. We found that most customers choose reverse osmosis under-sink filters with an average price of £275.81.

The reverse osmosis under-sink filters are available for purchase. We have researched hundreds of brands and picked the top brands of reverse osmosis under-sink filters, including Finerfilters, Geekpure, iSpring, FRIZZLIFE, Waterdrop.

Written by
Jennifer Fraser Avatar

Jennifer Fraser is a licensed contractor specializing in sales, maintenance, and kitchen, bathroom, and home appliances, tools, and utilities. She owns a store in Leeds where you can get any home and tool appliance. Jenny has a degree in literature, but she combines her knowledge and experience with her degree to publish DIY articles on solving home appliances issues to keep up the family enterprise.