Most refrigerator water filters have a generic counterpart. The question many ask is, “Is the generic filter as good as the name brand?” The answer to that question is both yes and no. It would depend on the product. However, most generic filters are just as effective as the brand name filter, but some do not offer the same level of quality.
What to Look For
The main thing you want to pay attention to when looking at contaminant removal for fridge filters is whether or not and how well, the system will remove chlorine, VOCs (Volatile Organic Compounds), heavy metals (lead and mercury), cysts, particulates, and turbidity. These contaminants are the primary contaminants that any effective carbon filtration system will remove, whether it is a refrigerator filter or any other water filtration product.
Important Note: If the manufacturer of your fridge water filter isn't also the manufacturer of your fridge, then they're not allowed to make any claims regarding contaminant removal once the filter is put in your fridge.
Probably the best way to know whether or not the filter you have is an effective one is to look for NSF certification. NSF sets standards that each product must meet in order to receive certification. The products are tested by a separate, third party in order to meet those standards.
This is not to say filters that aren't NSF certified aren't going to be effective. None of the generic filters are NSF certified, but because they are manufactured to the same specifications as the brand name counterparts, they are usually just as effective.