The 5 Best Under-Sink Water Filters of 2023

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. Its 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 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. We should note, however, the filter-replacement cost with this unit is more than most, so it's more expensive to operate throughout the year.

While we haven’t tested this system, Culligan is a trusted name in water filtration with a well-established record from past Good Housekeeping reviews. Besides its low initial cost, replacement filters are relatively affordable. 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 smaller households.

Our engineers found that Waterdrop's tankless design saves space compared with traditional reverse osmosis (RO) systems and is more water 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 roundup, the Waterdrop is not intended for well water, since the presence of large particulates can cause clogging.

The Brondell under-sink water filter costs less than many reverse osmosis (RO) systems. We're still completing our in-home evaluation, but initial assessments have been positive so far, especially the ease of setup and how simple it is to swap filters in and out. The Brondell, which is safe for well water, is also extremely compact for an RO system. As for expected performance, our engineers note that the system is certified under NSF/ANSI Standards 42, 53, 58 and 372. That means it will deliver 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 ten times more efficient than traditional RO systems, according to the brand. Our experts will verify that claim, and share any other relevant findings, as soon as testing is complete.

If cabinet storage space is at a premium in your kitchen, you’ll appreciate the compact design of MultiPure’s under-sink water filter. In field 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, and it’s also easy to replace the filter. Certified to NSF standards 42, 53 and 401, the solid carbon block filter 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. However, the dispenser isn't quite as sturdy as those we've evaluated on other models.