What are faucet water filters used for?

Faucet water filters are used to filter tap water right at the point of use by attaching directly to the end of the kitchen faucet, so the water is filtered as it comes out of the tap. They reduce contaminants and improve the taste and smell of the water, commonly cutting chlorine taste and odor, sediment and various impurities, giving you filtered water on demand for drinking, cooking and filling the kettle. A switch or diverter on the unit lets you toggle between filtered water for drinking and unfiltered water for jobs like washing up, so you only use the filter when you need it. Our Best Faucet Water Filters compares five of them.

What a faucet water filter is

A faucet water filter is a compact filter unit that screws or clips onto the end of your kitchen tap, in line with the water flow, so tap water passes through its filter cartridge before it leaves the spout. Inside is a filter medium, often activated carbon and sometimes other media, that traps or reduces impurities as the water flows through. Most have a small lever or switch that diverts the water either through the filter or straight out unfiltered.

Its defining feature is that it filters at the point of use, on the tap itself, rather than treating all the water in the house or sitting as a separate jug. That makes it a simple, installed-on-the-tap way to get filtered water directly from the faucet whenever you turn it on and select filtered mode. Understanding that it is a tap-mounted, on-demand point-of-use filter explains both what it is used for and how it differs from jug filters and under-sink or whole-house systems.

Improving taste, smell and reducing contaminants

The core use is improving the water and reducing what is in it. Most faucet filters use activated carbon, which is very effective at reducing the chlorine taste and smell that makes tap water unpleasant to some, so a major use is simply making tap water taste and smell better for drinking and in tea, coffee and cooking. Many people fit one chiefly to get rid of that chlorine taste and have more pleasant drinking water on tap.

Beyond taste, faucet filters are used to reduce a range of contaminants, with the exact ones depending on the filter, commonly sediment, some chemicals, and, on filters certified for them, particular contaminants, improving the water’s quality as well as its taste. What a given filter reduces varies by model and its certification, so people choose one that targets the contaminants they are concerned about. So the headline uses are better-tasting, better-smelling water and reduced impurities, delivered straight from the tap.

Filtered water on demand, and the switch

A key use of the faucet filter’s design is giving filtered water on demand, directly and in quantity, without the wait or limited capacity of a jug filter. Because it filters as the tap runs, you can fill a glass, a pot, the kettle or a bottle with filtered water straight away and in any amount, which suits drinking and cooking throughout the day without refilling and waiting for a jug to drip through.

The diverter switch is central to how it is used. You flip the lever to filtered mode when you want filtered water for drinking or cooking, and to unfiltered mode for tasks that do not need filtering, like rinsing dishes, washing hands or cleaning, which both saves the filter from unnecessary use and extends its life, since the cartridge only works when selected. This lets a faucet filter serve as your everyday drinking-water source while leaving the tap’s full normal flow available for everything else, which is a big part of its practicality.

Who uses them and how they compare

Faucet water filters are used by people who want filtered drinking and cooking water conveniently and cheaply without plumbing changes. They appeal to those who dislike the taste or smell of their tap water, want to reduce certain contaminants, or prefer filtered water to buying bottled water, and because they simply attach to the tap, they suit renters and anyone wanting an easy, low-cost, no-installation filter, including in kitchens without space for a jug in the fridge.

It helps to see how they compare, which shapes their use. Faucet filters are more convenient and higher-capacity than jug filters and need no fridge space, but they attach to the tap (so fit must suit your faucet) and the cartridge needs replacing periodically as it fills up. They are simpler and cheaper than under-sink or whole-house systems, though those filter more or treat all the water. So faucet water filters are used as a simple, on-demand, point-of-use way to get better-tasting, reduced-contaminant water straight from the kitchen tap, with a switch to use the filter only when needed, which suits everyday drinking and cooking for many households.

The short answer

Faucet water filters are used to filter tap water at the point of use by attaching directly to the kitchen faucet, so the water is filtered as it leaves the tap. Their main uses are improving the water’s taste and smell, especially cutting chlorine taste and odor with activated carbon, and reducing a range of contaminants depending on the filter, giving better, cleaner drinking and cooking water. Because they filter as the tap runs, they provide filtered water on demand in any quantity for glasses, pots, the kettle and bottles, and a diverter switch lets you choose filtered water for drinking and cooking or unfiltered flow for washing up, which also extends the cartridge’s life. They are a simple, low-cost, no-plumbing filter that suits renters and anyone wanting convenient filtered water without a jug or an installed system, with the cartridge replaced periodically and the fit needing to suit your tap.