6 Top-Tested Water Filters for Cleaner Drinking Water

Engineers, chemists, product analysts, and home improvement experts in our Home Improvement Lab evaluate water filters to identify the best options for a range of household needs. Over the years, we’ve tested more than 50 water filters and continually monitor the market for new models.

In Lab testing, we assess each filter’s capacity, setup process and, for pitchers, ease of pouring. We review the instruction manuals for clarity and note whether pitcher components are dishwasher-safe. We also measure filtration speed (how quickly a cup of water is filtered) and the usable volume of the reservoir.

To verify manufacturers’ contaminant-removal claims, we analyze third-party data, paying close attention to NSF certifications (some standards cover only lead, like NSF 372, while others also include agricultural and industrial toxins, like NSF 401). Finally, we track filter lifespan and calculate the annual replacement cost based on the maker’s recommended schedule.

✔️ Type: These are the main options for filtering drinking water that comes from the kitchen tap.

• Pitcher-style filters are the simplest, most affordable option, but you need to fill them by hand, and they can only deliver a certain amount of filtered water at a time.
• Under-sink filters are integrated into your home's plumbing system, delivering filtered water from a dispenser typically located next to your kitchen faucet. They're the most unobtrusive way to get filtered water, but also the most expensive.
• Faucet-mounted filters attach to the kitchen sink; installation is usually tool-free and DIY-friendly. But they look clunky and don't work with popular pull-down faucets.
• Whole-house filters, also known as "point of entry" systems, are installed at the main water line to treat all the water entering your home, whether from the municipal water supply or a well on your property. They require professional installation and maintenance, but they deliver the most comprehensive water treatment.

✔️ Capacity: For pitchers and dispensers that hold water after it's filtered, pay attention to size and weight. Larger containers mean less refilling, but they're often heavier and take up space in the fridge. A countertop model saves space in the refrigerator and often holds more water, but it requires counter space and delivers room-temperature water.

With under-the-sink and faucet-mounted filters, you don't need to worry about size or capacity because these filter water on demand.

✔️ Filtration method: Many filters incorporate multiple filter types to achieve various contaminant removal. The contaminants they remove can vary widely. The surest way to determine this is to check which NSF standard the filters are certified to. For example, some standards cover only lead, such as NSF 372, while others also include agricultural and industrial toxins, such as NSF 401. Otherwise, here are the different water filtering methods:

• Activated carbon is the most common water filter. The carbon-based filter acts like a magnet, absorbing contaminants from the water. Multi-stage filters, or 2-stage filters, might also include a pre-filter to remove larger sediment, as well as a second carbon filter to improve odor and taste. If necessary, there may even be a third filter, maybe with an additional carbon block or a UV sterilizer to kill bacteria and viruses.
• Reverse osmosis (RO) is a newer type of filter that captures contaminants by pushing pressurized water through a semipermeable membrane. While extremely effective, it's more expensive and less efficient—many systems require a tank that won't fit under your sink. Reverse osmosis filters are only used in water systems because they require pressure to work. Our experts first recommend testing your water to determine whether a conventional filter meets your filtration needs. Most water filters use either a carbon filter or a reverse osmosis water filter, which can also include a carbon filter.
• Ultrafiltration (UF) is another technology you might also hear about. Like RO, it forces water through semipermeable membranes. Because the pore size of UF membranes is larger, these systems don't capture all contaminants, including total dissolved solids (TDS) such as chlorine and fluoride; we did not review any UF systems for this reason.
• Mineral/alkaline filter adds minerals such as potassium, magnesium, and calcium. According to the Mayo Clinic, alkaline water has a higher pH level than plain tap water and some studies also suggest that alkaline water might help slow bone loss. However, further studies are needed to determine whether these benefits are long-term.

✔️ Filter replacement frequency: Check how often you have to replace the filter. If you dread changing the filter or simply forget, you may want to look for a long-lasting filter. Also, if you buy filters for the water pitcher and the sink, you'll have to remember to change each one separately.

No matter which water filter you choose, it's no good if you don't change it as recommended. The performance of the water filter depends on the quality of the water source and whether or not the filters are replaced regularly. Some models come with indicators, but if a model doesn't include one, a slower flow rate or different-colored water are signs that you need to change the filter.

✔️ Price: Consider both the upfront price of the water filter device and the filter refill costs. A water filter could cost more initially, but the price and frequency of the filter refills may save money over the long term. But that's not always the case, so be sure to calculate the yearly cost of replacements based on the recommended change schedule.

If you’re not sure about your water quality, check the Tap Water Database, managed by the Environmental Working Group (EWG). It’s free and easy to search, and it has information for all states.

Enter your zip code or search your state to find details on your drinking water quality based on EWG standards (which are stricter than those of the government). If your tap water does exceed EWG health guidelines, consider buying a water filter.

Opting for bottled water is a short-term solution to potentially unsafe drinking water, but it creates a larger problem with serious long-term implications around pollution. Americans throw away 30 million tons of plastic each year, of which only 8% is recycled. The majority ends up in landfills because there are many different regulations about what can be recycled. Your best bet is to get a water filter and a reusable water bottle—some even have built-in filters.

Our team of home and health experts at the Good Housekeeping Institute constantly tests water filtration products, both in our Lab and in the homes of expert testers.

Dan DiClerico has been writing about the residential water filter market for 25 years, reviewing dozens of products and systems from all the leading brands. In his role as director of the Home Improvement and Outdoor Lab at the Good Housekeeping Institute, DiClerico oversees water filter testing alongside our health and technical experts.

Kitchen Appliances & Cooking Lab Senior Director Nicole Papantoniou contributed insight on the ease of use of pitchers and countertop filters.

We also consult with outside organizations, including experts from NSF International, the organization that develops public health standards and certification programs for the industry, and the Water Quality Association (WQA), a not-for-profit trade group representing the U.S. water treatment industry.