Best under-sink water filters
Under-sink systems treat water at the kitchen tap and deliver the lowest cost per gallon of any point-of-use filter. The health-standard models (NSF/ANSI 53 and 58) also cover the most contaminants — lead, VOCs, cysts, and often PFAS.
125 certified under-sink models in our database · ranked by independent certification and cost per gallon · no paid placement.
Amazon prices as of October 20, 2026 at 2:01 PM ET. Prices can change; the price on Amazon is the one that counts. As an Amazon Associate we earn from qualifying purchases; some links are affiliate links and we may earn a commission at no extra cost to you. Disclosure.
How the top under-sink filters compare
| Filter | Certified for | Contaminants | Price | ¢/gal | |
|---|---|---|---|---|---|
| Multipure Aquaperform | Arsenic, Asbestos, Chlorine / chloramine +11 | 14 | $765 | — | Check price |
| Aquasana AQ-5200 | Asbestos, Chlorine / chloramine, Cryptosporidium +9 | 12 | $112.49 | 14.8 | Check price |
| Aquasana AQ-5300 | Asbestos, Chlorine / chloramine, Cryptosporidium +9 | 12 | $125.99 | 14.0 | Check price |
| Multipure Aquaversa | Asbestos, Chlorine / chloramine, Cryptosporidium +6 | 9 | $620 | — | Check price |
| 3M 3MDW301 | Asbestos, Chlorine / chloramine, Cryptosporidium +4 | 7 | $294 | — | Check price |
| Pentair OmniFilter RS14 | Chlorine / chloramine, Cryptosporidium, Giardia +3 | 6 | $9.35 | — | Check price |
| Pentair OmniFilter CBF3 | Chlorine / chloramine, Cryptosporidium, Giardia +3 | 6 | $92.36 | 23.1 | Check price |
| Aqua-Pure 3MFF100 | Chlorine / chloramine, Cryptosporidium, Giardia +2 | 5 | $318.95 | — | Check price |
| Pentair Easy Flow | Chlorine / chloramine, Cryptosporidium, Giardia +1 | 4 | $139.99 | — | Check price |
| Aqua-Pure AP-DWS1000 | Chlorine / chloramine, Cryptosporidium, Giardia +1 | 4 | $431.67 | 27.8 | Check price |
| Aqua-Pure AP-DWS1000 LF | Chlorine / chloramine, Cryptosporidium, Giardia +1 | 4 | $431.67 | 27.8 | Check price |
| Pentair PB55-20 | Cryptosporidium, Giardia, Lead | 3 | $160.67 | — | Check price |
Amazon prices as of October 20, 2026 at 2:01 PM ET. Prices can change; the price on Amazon is the one that counts. As an Amazon Associate we earn from qualifying purchases; some links are affiliate links and we may earn a commission at no extra cost to you. Disclosure.
See all 145 under-sink filters →
How to choose an under-sink filter
Match it to your water. The best filter is the one certified for what's actually in your water. Look up your ZIP to see your contaminants, then confirm the filter's certified claim list covers them.
Certification tiers to know. NSF/ANSI 42 = aesthetic (taste, chlorine); NSF/ANSI 53 = health (lead, VOCs, cysts); NSF/ANSI 401 = emerging contaminants (pharmaceuticals). A filter is only credited for the exact claims it lists.
Installation & upkeep. Mounts under the sink; connects to the cold line. Basic DIY. Expect to replace the element about 2×/year; the running cost of refills usually matters more than the sticker price.
Frequently asked
What's the most important thing when buying an under-sink water filter?
Certification for the specific contaminant you care about. "NSF certified" is not one thing — a filter certified for lead (NSF 53) may do nothing for PFAS or fluoride, and NSF 42 only covers taste and chlorine. Check the exact certified claim, which we list for every filter.
Are these filters actually certified, or just "tested to" a standard?
Every filter here is listed in the public certification database of NSF, WQA, or IAPMO — meaning an independent body verified its claims. We never count "tested to" marketing claims that aren't backed by a listing.
How do you rank them — does anyone pay for placement?
No. We rank by independent certification coverage and true cost per gallon, computed before any buy link is attached. See our methodology.
Rankings use NSF/WQA/IAPMO public certification data and computed cost per gallon. We only attach a buy link when we can verify the retail listing is the certified model. Some links are affiliate links — see our disclosure.