According to EatByDate, fish stays fresh in the refrigerator for 1 to 2 days. However, proper storage in an airtight container is key to preserving fish and keeping it fresh. Cooked fish has a slightly longer shelf life of around 5 to 7 days.
Typically, fish spoils relatively fast. Before consuming fish, it is best to look for signs of spoilage, such as a slimy coating or strong fishy smell. Any fish that has signs of spoilage should be discarded. Fish has a longer shelf life when frozen. Most fish varieties last anywhere from 6 to 9 months in the freezer when properly stored in a freezer-safe container.