The shelf life of uncovered pizza in the fridge can vary depending on various factors such as the type of toppings, how it was stored, and the freshness of the pizza when initially refrigerated. In general, it's best to follow the same food safety guidelines for any perishable food.
When pizza is left uncovered in the fridge, it can start to dry out, and its quality will degrade more quickly than if it were stored in an airtight container or wrapped in plastic wrap. Typically, pizza that is left uncovered in the fridge may start to lose its freshness and taste within 1-3 days.
If you have leftover pizza that was not properly covered and refrigerated within 2 hours after cooking, it's advisable to consume it within 1-2 days to ensure it is still safe to eat and to enjoy it at its best quality. After this period, there's a higher chance that the pizza could develop off-flavors or spoilage.
If you want to extend the shelf life of leftover pizza, consider transferring it to an airtight container or wrapping it in plastic wrap before refrigerating. This will help to preserve its moisture and prevent it from absorbing other odors in the fridge, keeping it fresher for a longer period.