Replacement parts, actually verified
The certification claims on replacement filters are checkable. So we check them.
Marketplaces are full of replacement filters that claim NSF certification. The certification databases are public. The Refill Report compares the claim on the listing to the record in the database, model by model, and publishes the full dataset every time.
Study № 1 · August 2026
What percentage of refrigerator water filters sold online are counterfeit or fake?We checked all 45 best-selling fridge filters against the NSF, IAPMO R&T, and WQA certification databases. 30 of 45 (67%) could not be confirmed certified for the exact model sold — and 56% of listings that advertise certifications claim credentials the databases don’t show.Fitment index
Which water filter fits your refrigerator?50 popular refrigerator models — the OEM filter each takes, plus every compatible aftermarket filter from our dataset with its certification verification status.15/45filters confirmed certified for the exact model sold
67%could not be confirmed against any certification database
56%of certification-claiming listings overstate what the databases show