Which item is used to evolve Porygon into Porygon2?

The item used to evolve Porygon into Porygon2 is Up-Grade. In the main Pokémon games, Porygon must be traded while holding an Up-Grade for the evolution to occur. This evolution method debuted with Pokémon Gold and Silver, which introduced Porygon2 as a Generation II upgrade to the original artificial Pokémon.

Up-Grade fits Porygon’s concept as a computer-created Pokémon. Its name suggests a software or hardware improvement, and Porygon2’s smoother, more rounded design reinforces the idea that it is an enhanced version. The trade requirement also reflects how several Pokémon evolutions were originally designed to encourage communication between players.

Players commonly confuse Up-Grade with the Dubious Disc. The Dubious Disc is used for the next stage of the family: Porygon2 evolves into Porygon-Z when traded while holding that item. Metal Coat is another trade-evolution item, but it applies to Pokémon such as Onix and Scyther. Linking Cord is a later alternative used in some games and does not change the canonical item associated with Porygon’s original evolution method.