7 Best Reverse Osmosis Water Filters Tested For 2026
Good Gear editors endorse products we’ve personally researched, tested, and genuinely love. Learn more about our methodology and business model here.
Depending on where you live, your drinking water may contain contaminants ranging from heavy metals to “forever chemicals” (PFAS) and microplastics. Reverse osmosis filters are a surefire way to clean the water you’re using around the house; they use a rigorous and multi-step process to trap impurities. They actually use a similar system to that used in bottled water — thus, RO systems are often called “bottled water without the bottle.” They range in terms of size, system, and cost, so we’ve rounded up a variety of verified solutions at different price points and for different home needs.
What is a reverse osmosis water filter, and what are the benefits?
RO is an advanced kind of filtration that cleans drinking water. If osmosis is liquid passing from high concentration to low concentration through a barrier to achieve equilibrium (think: water flowing into plant roots), then the reverse process is to push water through a membrane to keep pollutants trapped while leaving the purified liquid behind.
There’s a whole host of contaminants that can occur in our water, including chlorine (which is used to disinfect water but can be left in trace amounts), heavy metals and lead (through runoff, corroded plumbing, and other issues), PFAS (through industrial waste and even consumer products), and volatile organic compounds or VOCs (through chemical products that can seep into soil and groundwater). It depends on your location; if you’ve never checked before, the EWG Tap Water Database or use My Tap Water can give you at least a basic sense of how much filtration you might need.
Reverse osmosis is one of the only technologies available that can actually remove total dissolved solids (TDS), a.k.a. the total concentration of dissolved substances in water, including smaller particles that other filters don’t capture. The most common RO systems are under the sink, which are usually larger and require some setup with your existing faucet, and on the countertop, which are usually smaller and have less capacity but are a less invasive solution. Recently, under-the-sink tankless RO systems have gained popularity, promising to take up less space and filtrate faster via an internal booster pump that filters water when you turn on the tap. But they don’t always perform as well as tank-equipped models.
Your RO solution depends on your specific needs: a countertop model will be easier to set up and store, but the capacity won’t be as high and (depending on the model) the filters might be smaller and not last as long. An under-the-counter model usually requires at least a little DIY, whether it’s adding a faucet adapter to an existing spout, installing another, second spout, or replacing your existing faucet with the new one.
There’s a wide variety of factors to consider when purchasing an RO system, including the level of filtration you need, whether you want remineralization (minerals put back into the water to make it taste better), and the pure-to-drain ratio that measures how much purified drinking water is produced compared to the excess wastewater sent down the sink. It’s also important to note that these systems can be expensive, with an added cost to replace the filters or parts that break, but some of these are HSA/FSA available and many go on sale throughout the year.
Why are independently tested water filters important?
- Each of your filters should be certified by the National Sanitation Foundation (NSF) and approved by the American National Standards Institute (ANSI). Water filtration is currently unregulated, and the NSF holds brands accountable to the claims they make on their site. Their certification also makes it easier to make an apples-to-apples comparison between different RO systems. You might also see the WQA (Water Quality Association), but they also use NSF/ANSI standards. If you see the acronym IAPMO, that is an accredited testing laboratory that certifies products to NSF standards.
- RO-selling brands might bill themselves as “meeting NSF standards” but don’t undergo actual third-party certification. So it’s important for brands to be transparent about how they test, what certifications they do have, and how else they ensure that their systems meet the highest standards of processing. Look carefully at the wording, if you’re doing your own research.
- Considering that customers usually look to RO filtration to reduce contaminants in their water, it’s important that any systems actually match their contaminant reduction claims. This is especially important for uncertified and low-cost brands, and TrustPilot and other third-party review systems may note when a brand is overpromising. Also, beware of false claims about level of filtration. Reverse osmosis by itself is not going to remove all contaminants; that will require a multi-step system.
- Filter quality is especially important for an effective RO system: not only is that going to offer more robust filtration, but it’ll also ensure that the filters last longer. Additionally, brands should be transparent about when filters need to be changed; if there’s no app or alert system to indicate when you need to change a filter, go based on the brand’s recommendation. If you want to test your filtration system by yourself (instead of having a plumber do it), you can buy a TDS meter—which usually costs about $15–and test your water for solids before and after it goes through the filter. A working filter will be rejecting (removing) between 85 and 95% TDS.
Our criteria:
After researching, corresponding with brands, combing through customer reviews, and even testing a few ourselves, we’ve chosen the best reverse osmosis water filters for cleaner, better-tasting water at home. We update this list regularly with new, emerging favorites, and all of our picks are evaluated to meet the following criteria:
- PERFORMANCE | Reverse osmosis systems are designed to help reduce a wide range of contaminants while improving water taste and quality. We’ve ranked brands based on filtration capabilities, certifications, transparency, and our experience with them, where applicable.
- QUALITY & DURABILITY | We’ve tested some of these systems ourselves, and relied on customer reviews otherwise, to select brands that make high-quality products that are built to last.
- THIRD-PARTY TESTED | Each brand offers high-quality filtration systems with independently verified testing or certifications. We prioritized options with transparent contaminant testing.
Looking for more than just tap water? We’ve rounded up the smart water bottles that can take your clean water on the go, and air purifiers for indoors that can remove air pollutants that are just as potent.
1. AquaTru
Best For | Our overall favorite
System Type | Both countertop and under-sink
Prices starting at | $325 for the AquaTru Carafe
Inventors of the world’s first countertop reverse osmosis system, AquaTru allows for true RO filtration without plumbing or complex installation. With a mission-driven mindset, they’re committed to local communities, including on-the-ground support in Flint, Michigan, and Southern California during the 2025 wildfires. There are a few AquaTru options, but they all utilize the same four-stage “Ultra Reverse Osmosis” process. In the first two stages (done together in a single filter), a pre-filter captures rust, sediment, and any other larger particles, and a carbon filter removes chlorine and chloramines (chemical compounds containing chlorine and ammonia). Stage three is the actual reverse osmosis process, which gets rid of inorganic chemicals:, microplastics, arsenic, lead, nitrates, chromium-6, and heavy metals. And, in the final stage, a filter removes VOCs, including rocket fuel, residue from prescription drugs, and PFOS.
All of their systems come with filters already — meaning you don’t have to purchase them separately — and you won’t have to replace them for a while, since the three filters are designed to last six months or more. The under-sink model is best for the most high-volume use, and the carafe (64 fl oz) and classic (96 fl oz) work for a smaller volume, like one might find in a family household. Everything runs on electricity, meaning you plug the devices into the wall.
Our Editor’s Review | “I sought out AquaTru after discovering lead in my apartment’s water. After two months of testing, I’m generally happy with the AquaTru system. AquaTru water tastes great, doesn’t take up too much space under the sink, and had a pretty straightforward installation. I consider myself generally pretty handy, but I ended up getting professional help installing for peace of mind drilling into the existing pipes.” – Ashley, Senior Editor (Read the full review.)
2. CloudRO
Best For | Simple but user-friendly RO
System Type | Under-sink
Prices starting at | $599
With tons of 5-star reviews, both from users and testers, CloudRO is generally considered the gold standard for under-the-sink RO systems. With a promise of removing 99% of toxins in water, they are certified NSF 58, which is the best for RO systems and captures the largest amount of TDS in water. If you’re curious or want to learn more, Cloud has a robust NSF FAQ section that’s designed to be both in-depth and easy to understand.
As for the actual unit, it’s a quiet device that sits under the sink and connects to an app you can use to assess drinking water quality and battery and filter status. It uses the pressure from water pipes to “push” the water through and then stores it in a tank under the sink, but it’s made to maximize volume without adding a ton of space. The drinking water also rates highly among customers for tasting great, due to the Cloud’s remineralization process that adds minerals back into the water and increases the pH. The remineralization is the last step in their four-part filtration, after sediment filter, carbon block pre-filter, and RO membrane. The core system is designed to last at least a decade, and the filters and battery can last six months or more, depending on usage. One thing to note: if you intend to use their included faucet, there’s a DIY component to install it. But Cloud bills itself as being user-friendly, and reviews back this up.
Customer Review | “We love it, the taste, the feeling, the app, everything about it. The installation was easy and fun, I let my 7 yr old help me with the whole installation and it was fun to do it together.” – Jonas P. (Read more reviews.)
3. Waterdrop
Best For | Fast, tankless RO
System Type | Both countertop and under-sink
Prices starting at | $199 for the C1S Countertop CoreRO System
Waterdrop offers a ton of options for customers to personalize their RO experience. Beyond the standard under-sink and countertop options, they also offer hot and cold RO systems, dual flow RO (filtered water for washing dishes and RO water for drinking and cooking), and combo kits with multiple years’ worth of filters. Because there’s a lot to assess, the website lets you compare different options to see which one might work best for your home.
Depending on the model, the Waterdrop RO systems use a 6, 7, 8, or 10-stage filtration process. One of their best sellers, the tankless Waterdrop G3P600, promises to fill an 8 oz cup in 8 seconds and utilizes an 8-stage process (tested by a third party) that is still NSF 58 certified like other top RO systems. With a 3:1 pure-to-drain ratio, it wastes less water with three gallons of pure water for every one gallon of waste. It has a smart display faucet, which is designed to show water quality and let you know when a filter needs replacing. Their more high-volume models, like the Waterdrop X12, are even faster and higher-volume tankless systems, but some reviewers note that such speed and capacity aren’t really all that necessary for a residential setup. In other words, a smaller, slightly slower, less expensive option may be perfect for a home RO system.
Customer Review | “We are very pleased with the Waterdrop water filtration system. I was looking for an affordable option for filtered water in our rental. This has been great. It’s a workhorse. Providing water for ALL our water and beverage needs.” – Fredia H. (Read more reviews.)
4. Delta Clarifi
Best For | A well-certified, long-lasting RO
System Type | Under-sink
Prices starting at | $1,142
Coming in as the priciest option on this list, Delta Clarifi is a robust system. It’s tankless with a 6-stage filtration system that removes more than 90 contaminants and is the most certified tankless RO system in its class (NSF 42, 53, 58, 372, and 401). Their carbon and RO filters are designed to have a two-year lifespan, so you can go longer between buying replacements. And it’s designed specifically with the mindset of saving space compared to other models, with a small and thin design that fits unobtrusively under the sink.
With that in mind, there are some extra costs associated with buying the Delta Clarifi. Purchasing a faucet costs extra (it’s not necessary if you’re using your own faucet), and buying a remineralization cartridge costs extra, too. Reviewers did note that the system was louder than others they’ve tried, and some (but not all) customers said the installation was a bit trickier than other, easier DIY options. Delta has various guides to help with this process, including setup videos. Factoring all that in, a lot of reviewers noted that it performed better than other RO systems they’d used and, considering how long it lasted, was a worthy investment.
Customer Review | “I’m really impressed with this filtration system! The water tastes super fresh and clean, such a big difference right away. I also love that it’s small and doesn’t take up much space under the sink at all. My husband was able to install it pretty easily, which was a huge bonus. Overall, a great upgrade for our kitchen and totally worth it!” – Mimi A. (Read more reviews.)
5. Dreo
Best For | Cost-effective, no-fuss RO
System Type | Countertop
Prices starting at | $170 for the RO Water Filter 112
With the least expensive option on this list, Dreo offers exclusively countertop RO options. Despite the lower price point (the most expensive option comes in at $347), reviewers note that there are several key specifications that help it go toe-to-toe with some of the more expensive models. Beyond the 7-step filtration that removes 1,000 impurities from the water and a 3:1 pure-to-drain ratio, there’s a built-in real-time TDS sensor to assess how well the RO filter is working. There’s an autofill function for the pitchers and a self-cleaning function, the latter of which helps the device from breaking down more easily. Furthermore, if the components (water tank, filter, and pitcher) break or stop functioning, you can buy replacements easily; a descaling kit is also available for easy maintenance.
Reviewers do note that the smaller capacity of the tank makes for a lot of refilling — which, if you’re using water constantly in your home, might be too much maintenance. The flow is also slower than some of the other options on this list. But for a small kitchen, or for anyone who doesn’t want to mess with their under-sink plumbing, it’s a good option.
Customer Review | “We love our DREO. Our tap water in the apartment is okay, but doesn’t taste the best. We were buying water and worried about plastic leeching until we found this product – water tastes great now and it improves our coffee, kombucha, even the clarity of our ice cubes, etc.” – Vanessa G. (Read more reviews.)
6. Frizzlife
Best For | Affordable tankless RO
System Type | Both countertop and under-sink
Prices starting at | $238
Frizzlife mostly offers tankless RO systems, with one countertop option. But — compared with pricier tankless systems — these still hold up in terms of quality. It’s easy to compare models online to determine which one you need, but they’re all quite compact and easy to install. Setup’s designed to be straightforward, and filters can be twisted and pulled out to quickly replace them. Frizzlife actually has a chart for which systems are good for which contexts, from apartment dwellers to high-use homeowners.
Customers appreciate the 8-stage RO filtration with a 0.0001 micron RO membrane. Another positive feature is the 2:1 low drain ratio (although some reviewers have noted that number can vary depending on volume). Alkaline remineralization is built into the filtration system as well as a carbon block to decrease odor, which means there’s no need to take an extra step to make the water taste better. As with other tankless models, the water comes out quickly, particularly for those marked with a high gallons per day (GPD) designation. Their bestselling Frizzlife 600, which is designed for residential family use, has a real-time TDS display to check water quality and filter status, as well as a fast flow for ease of use.
Customer Review | “This purifier is perfect for our multi-generation household. With 600 GPD capacity, we never worry about running out of water – enough for cooking, tea, boiling water. The alkaline + remineralization filter makes the water smooth and not flat, and I feel safe drinking it long-term. Once installed, it’s set-and-forget; just replace filters regularly. Recommended for large families.” – Daniel K. (Read more reviews.)
7. iSpring
Best For | A variety of RO solutions
System Type | Both countertop and under-sink
Prices starting at | $420 for countertop RO system, $230 for under-sink RO system
It’s hard to beat iSpring for sheer variety of options and price points. The company was founded back in 2005 (before several of the companies on this list). As such, their website isn’t as user-friendly as others that were designed more recently — you have to pore over the specs to note the differences between models, for example. But customers rave about the customer service and depth of detail, once you know what you’re looking for. Some of their units are sold at online retailers, but the brand website has the full offerings if you’re looking to browse every option.
To help narrow down the choices, it can be helpful to understand whether you want a classic, tankless, countertop, or deionizer model. Their bestselling RCC7AK model is reasonably priced for an under-sink model ($242), and its 6-stage filtration with alkaline remineralization reportedly results in terrific tasting water. iSpring also has varied countertop systems, including their RCD100SPKHC model that makes cold, hot, and sparkling water. Reviewers do note that their products have lower pure-to-drain ratios than others on this list, and (depending on the model) they have experienced wear and tear on the equipment. Third-party verification also ranges between models and by contaminant. But for the discerning RO user who wants to hone in on their exact specifications, this has an impressively wide range.
Customer Review | “We have been looking for a RO system for a while. Currently, we rent an apartment, so no drilling holes, no changing the water supply… This over the counter system perfectly meet[s] our needs. The shipment was fast and the installation was not hard at all. Simply plug it in and the unit will take care of the rest. We were concerned if it will make any noise when we sleep, but actually we wouldn’t have to worry [about] it at all. It stays super silent over the night. Love it!” – Irina (Read more reviews.)
Featured image by Delta Clarifi
