How we verify
Our entire value is accuracy. Here is exactly how every filter fitment and NSF claim on FiltersDex is built, checked, and dated.
1. NSF claims come from NSF's own certified-product listings
Every contaminant we say a filter is certified to reduce is pulled from NSF's own published certification listing for that filter, broken out by standard (42, 53, or 401). We never infer or assume a certification from a filter's marketing copy or packaging alone.
2. Fridge fitment comes from retailer application data
We build each filter-to-model match from established retailer compatible-model listings - the same cross-reference data a parts counter or filter retailer sells against. Where a listing is incomplete, we leave the field blank rather than guess.
3. Part numbers and cross-references are traced, not invented
The "also known as" part numbers on each filter page come from real cross-reference listings. We do not fabricate part numbers, prices, or NSF claims a filter has not actually earned.
4. Always confirm before you buy
Fridge model revisions and filter compatibility can vary. We surface what our data shows, but the final word is the model label on your appliance and the filter's own certification sheet. We're a reference, not a substitute for checking your fridge.
Why FiltersDex is free
FiltersDex is free to use and always will be. We make money from small commissions when you buy a filter through some of the "where to buy" links, at no extra cost to you. We show the same specs to everyone regardless of who pays us, and our answers aren't influenced by any retailer or brand.