The right water filter depends less on which type you buy than on what’s actually in your water. A reverse osmosis system overkills the job if your only concern is chlorine taste; a basic carbon pitcher won’t touch lead, PFAS, or arsenic no matter how often you change the cartridge. The starting point for any informed filter purchase is identifying which contaminants are present in your specific supply, then matching filtration technology to those specific problems.
This category covers the contaminants most commonly found in U.S. drinking water, with a dedicated buying guide for each. The headline issues — PFAS (forever chemicals), lead, fluoride, chlorine, microplastics, and hard water minerals — get their own in-depth roundups covering which filters reliably remove them and which only claim to. Less common but health-critical contaminants like arsenic, nitrates, bacteria, and chromium 6 also have dedicated guides for households dealing with those specific concerns, particularly well water owners and residents near industrial sites.
If you haven’t tested your water yet, our hub on what contaminants are in tap water explains the most common issues and how to identify them. For the most urgent contaminant of 2026 — PFAS, in light of recent EPA rule changes — our guide to the best water filters that remove PFAS covers the certified options across every filter type.
Each guide below approaches the contaminant from the same angle: what it is, where it comes from, what the health concerns are, and which specific filters carry the independent certification needed to remove it.
Most filters don’t remove microplastics. We cover the only certified options that actually do — RO systems, specialized pitchers, and what the new EPA regulations mean.
Chlorine makes water taste and smell like a pool. We cover the best certified filters for every budget — and explain why chloramine requires a different solution entirely.
Hard water damages appliances and tastes flat. We cover the best filters, softeners, and conditioners for every budget — and explain when you need each one.
Lead in water can’t be seen, tasted, or smelled. We cover the only NSF-certified filters that actually remove it — from pitchers to under-sink systems — for every budget.
Most filters don’t remove PFAS. We cover the only certified options that do — from RO systems to pitchers — plus what the EPA regulations actually mean for your tap water.