What's in your water?
Enter your ZIP code to find out - then match your contaminants to NSF-certified filters that actually remove them.
Free Water Filter Tools
No email required. No brand bias. Just data.
Contaminant Matcher
Most popularEnter your ZIP code to see what's in your water and which filters are certified to remove it.
Open toolFilter Cost Calculator
Compare the true cost of ownership - purchase price plus replacement filters over 1, 3, and 5 years.
Open toolRO vs Carbon vs UV
Answer a few questions about your water and we'll recommend the right filtration technology.
Open toolWhole-House Sizing
Calculate the flow rate you need based on your home size and fixture count.
Open toolWell Water Planner
Build a multi-stage treatment chain based on your well water issues.
Open toolReplacement Tracker
Track when to replace your filters and what it costs annually.
Open toolMost Searched Contaminants
Learn what's in your water, where it comes from, and which filters remove it.
42
Filters with verified specs
100
US water systems mapped
3,038
ZIP codes covered
Every recommendation is backed by NSF certification data and EPA water quality reports.