XL Candy is a special type of candy in Pokemon Go that allows players to level up their Pokemon beyond level 40. It is different from regular candy and is much rarer to obtain. To start receiving XL Candy, players must reach Trainer Level 31. Some of the ways to obtain XL Candy include:

• Catching Pokemon: catching evolved forms of Pokemon guarantees XL Candy, while catching basic Pokemon may or may not provide XL Candy.
• Transferring Pokemon: transferring Pokemon may leave behind an XL Candy with its regular candy.
• Raids: catching Pokemon in raids guarantees XL Candy.
• Hatching eggs: the number of XL Candy received is higher when hatching eggs that require more walking.
• Converting regular candy: players can exchange 100 regular candy for 1 XL Candy, but this is not very efficient.

XL Candy is specific to Pokemon families, so players need to use Squirtle XL Candy on Squirtle, Wartortle, and Blastoise, for example. The quickest way to get XL Candy is to catch Pokemon, as players have a chance of receiving 1-3 XL Candy per catch.