Best gravity water filters: Berkey, Alexapure and more, with certification stated plainly (2026)
A gravity filter needs no power or water pressure: pour water in the top and let it drip through. That makes it a natural outage tool. But on November 9, 2026, we found no countertop gravity system here certified by NSF, WQA or IAPMO for lead or germs; ProOne's certified Big+ has been discontinued. So this page states each filter's status plainly, and the official advice on making water safe comes first.
By Tom Calder · Updated November 9, 2026 · 7 products, 4 of 7 price-tracked
Our picks
Alexapure Pro
A stainless countertop gravity unit with published lab tests
Platypus GravityWorks 4L
Fast, light gravity filtering for a group or a go-bag
All 7 compared
| Filter | Capacity | Flow (maker) | Filter life (maker) | Certification | Price |
|---|---|---|---|---|---|
4 L dirty bag + 4 L clean bag · 1.75 L/min · 1,500 L per cartridge · Not certified (maker: meets EPA and NSF guidelines for bacteria and protozoa) Fast, light gravity filtering for a group or a go-bag | 4 L dirty bag + 4 L clean bag | 1.75 L/min | 1,500 L per cartridge | Not certified (maker: meets EPA and NSF guidelines for bacteria and protozoa) | |
Our verdictOur verdictResearched Two bags and a hollow-fiber filter: hang the dirty bag and it filters 1.75 liters a minute into the clean one, with no pumping. It removes bacteria and protozoa, not viruses or chemicals, and weighs under 12 oz. It was out of stock at the maker when we checked. Best for Fast, light gravity filtering for a group or a go-bag Good
Worth knowing
Who shouldn't buy it: Don't buy it if you need a countertop unit for daily home use: a stainless system holds more. | |||||
2.5 gal upper chamber · About 1.67 gal/hour per filter (maker) · Up to 200 gallons per filter · Not certified; lab-tested to NSF/ANSI 42, 53, 401 (maker) A stainless countertop gravity unit with published lab tests | 2.5 gal upper chamber | About 1.67 gal/hour per filter (maker) | Up to 200 gallons per filter | Not certified; lab-tested to NSF/ANSI 42, 53, 401 (maker) | |
Our verdictOur verdictResearched A 2.5-gallon stainless gravity filter with a lab report the maker publishes: tested to NSF/ANSI 42, 53 and 401, but not certified, and not listed by NSF, WQA or IAPMO. Filters are rated up to 200 gallons each, far less than Berkey's claim. Alexapure itself says to keep following boil-water guidance for unsafe water. Best for A stainless countertop gravity unit with published lab tests Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want a certified filter: a certified pitcher like Brita Elite or ZeroWater has a listing. | |||||
1 gal bladder · Up to 100,000 gal (maker rating) · Not certified (maker lab tests) The cheapest gravity setup that removes bacteria and protozoa | 1 gal bladder | — | Up to 100,000 gal (maker rating) | Not certified (maker lab tests) | |
Our verdictOur verdictResearched A 1-gallon bag with Sawyer's 0.1 micron MINI filter on a hose: hang it and let it drip. Sawyer says it removes 99.99999% of bacteria and 99.9999% of protozoa, but not viruses. It's light and inexpensive, and was out of stock at the maker on November 9. Best for The cheapest gravity setup that removes bacteria and protozoa Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want a filter that also reduces lead or chemicals: hollow fiber doesn't. | |||||
 1.5 gal · Up to 2.75 gal/hour · 3,000 gal per element (maker) · Not certified (Black Berkey: maker-reported lab tests) Small households that already trust Berkey | 1.5 gal | Up to 2.75 gal/hour | 3,000 gal per element (maker) | Not certified (Black Berkey: maker-reported lab tests) | $327 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched Berkey's smallest stainless unit, for 1 to 3 people. Plainly: Black Berkey elements are not certified by NSF, WQA or IAPMO to any NSF/ANSI standard; Berkey reports third-party lab tests. EPA ordered two Berkey sellers in 2022 and 2023 to stop selling Black Berkey filters, treating them as unregistered pesticide products because they contain silver as an antimicrobial; Berkey challenged this in court, and we found no final ruling. Berkey doesn't sell to California or Iowa residents, and on its own site the Travel Berkey was listed as out of stock or of limited availability, ordered through dealers, on November 9, 2026. Best for Small households that already trust Berkey Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want certified performance: nothing about Black Berkey is listed by a certifier. | |||||
 3.25 gal · Up to 4 gal/hour (2 elements) · 3,000 gal per element (maker) · Not certified (Black Berkey: maker-reported lab tests) Families of 2 to 4 who choose Berkey | 3.25 gal | Up to 4 gal/hour (2 elements) | 3,000 gal per element (maker) | Not certified (Black Berkey: maker-reported lab tests) | $458 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A bigger Berkey (3.25 gallons) for 2 to 4 people. The same plain facts apply: no NSF/ANSI certification for Black Berkey elements, EPA stop-sale orders still disputed in court, limited supply through dealers on Berkey's site, and no sales to California or Iowa residents. Best for Families of 2 to 4 who choose Berkey Good
Worth knowing
Who shouldn't buy it: Don't buy it if certification matters to you. | |||||
 4.5 gal · Up to 5.5 gal/hour (2 elements) · 3,000 gal per element (maker) · Not certified (Black Berkey: maker-reported lab tests) Big households (4 to 8) who choose Berkey | 4.5 gal | Up to 5.5 gal/hour (2 elements) | 3,000 gal per element (maker) | Not certified (Black Berkey: maker-reported lab tests) | $451 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched Berkey's 4.5-gallon unit for 4 to 8 people, taking up to six elements. Same facts: Black Berkey elements carry no NSF/ANSI certification, EPA stop-sale orders are disputed in court, it's limited supply through dealers on Berkey's site, and it isn't sold to California or Iowa residents. Best for Big households (4 to 8) who choose Berkey Good
Worth knowing
Who shouldn't buy it: Don't buy it if certification matters to you. | |||||
 2.25 gal · Up to 3.5 gal/hour (2 elements) · 3,000 gal per element (maker) · Not certified (Black Berkey: maker-reported lab tests) The best-known countertop gravity filter, with its caveats | 2.25 gal | Up to 3.5 gal/hour (2 elements) | 3,000 gal per element (maker) | Not certified (Black Berkey: maker-reported lab tests) | $415 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.Out of stockCheck price → |
Our verdictOur verdictResearched The 2.25-gallon Big Berkey is the famous one. Its Black Berkey elements are not certified to any NSF/ANSI standard; Berkey's own wording is that labs 'reported that the elements meet ANSI/NSF (Std. 53) protocol'. EPA ordered two Berkey sellers in 2022 and 2023 to stop selling Black Berkey filters, treating them as unregistered pesticide products because they contain silver as an antimicrobial; Berkey challenged this in court, and we found no final ruling. Berkey's newer Phoenix elements are NSF-listed for chlorine, taste and odor only. Berkey's site listed the Big Berkey as limited supply, ordered through dealers, on November 9, 2026, and not sold to California or Iowa residents. Best for The best-known countertop gravity filter, with its caveats Good
Worth knowing
Who shouldn't buy it: Don't buy it if certification matters to you, or you live in California or Iowa. | |||||
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Before you buy
Ask what it's certified for.
None of the stainless systems here has an NSF/ANSI listing for lead or microbes. Alexapure publishes a lab test to NSF/ANSI 42, 53 and 401; Berkey reports labs found its elements 'meet ANSI/NSF (Std. 53) protocol'. Tests aren't certification.
Countertop or hanging
Stainless countertop units (Berkey, Alexapure) hold 1.5 to 4.5 gallons for daily use; hanging bag systems (Platypus, Sawyer) weigh ounces and go in a go-bag.
Check filter life
Alexapure rates its filters at up to 200 gallons; Berkey claims 3,000 gallons per Black Berkey element; Platypus 1,500 liters per cartridge.
Microbes: hollow-fiber bag filters (Platypus 0.2 micron, Sawyer 0.1 micron) target bacteria and protozoa.
CDC says a filter needs an absolute pore size of 0.3 micron or smaller for bacteria and 1 micron or smaller for parasites, and that portable filters will not remove viruses.
Where you live: Berkey doesn't sell to California or Iowa residents, and Alexapure doesn't sell its Pro to California.
We verify every product's specifications against at least two independent sources, re-check its US price and stock on a schedule where we can track it automatically, and cross-check safety-relevant claims against official guidance. Every review is labeled Researched or Used and reviewed by us: where we've bought a product, or been sent it free, and used it ourselves, its review says which; where we haven't, our verdict is a considered spec-and-evidence comparison, not a hands-on test. When two products are close, commission can decide which one we pick. A clearly better product always wins. Read our full methodology →
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Common questions
Is Berkey NSF certified?
No. We found no Black Berkey listing with NSF, WQA or IAPMO. Berkey says labs reported its elements meet NSF/ANSI 53 protocol, which is a test claim, not certification. Its newer Phoenix elements are NSF-listed to NSF/ANSI 42 for chlorine, taste and odor only.
Can you still buy a Berkey?
Berkey's own site sells through dealers with limited supply, and not to California or Iowa residents. EPA ordered two Berkey sellers in 2022 and 2023 to stop selling Black Berkey filters, treating them as unregistered pesticide products because they contain silver as an antimicrobial; Berkey challenged this in court, and we found no final ruling.
Do gravity filters remove viruses?
None here claims to. CDC says portable filters will not remove viruses and recommends adding a chemical disinfectant such as chlorine or chlorine dioxide after filtering, or boiling.
Is a gravity filter good for a power outage?
It needs no power or pressure, which helps. But stored water comes first: Ready.gov says at least a gallon per person per day. A gravity filter is for when stored water runs out or tap water is under a notice, alongside boiling or disinfection.
What's a certified alternative?
For tap water, pitchers like Brita Elite (lead) and Culligan ZeroWater (lead and total PFAS) are certified to NSF/ANSI 53. They aren't purifiers for unsafe water either.