XL Candy is a resource in Pokemon Go that allows you to level up your Pokemon beyond level 40, which is the previous level cap. You can only start receiving XL Candy once you reach Trainer Level 31. The amount of XL Candy you need to level up your Pokemon is the same for every Pokemon, except for Shadow Pokemon, which require 360 XL Candy, and Purified Pokemon, which require 272 XL Candy.

There are several ways to obtain XL Candy in Pokemon Go:

• Catching unevolved Pokemon gives you a chance of receiving between x1 XL Candy and x3 XL Candy.
• Catching evolved, Legendary, or Mythical Pokemon guarantees you at least x2 XL Candy for evolved creatures, and a minimum of x3 XL Candy for Legendary and Mythical Pokemon.
• Successfully catching a Raid boss can get you XL Candy.
• Hatching eggs gives a chance of receiving XL Candy, with increased XL Candy amounts the longer it takes to hatch an egg.
• Transferring Pokemon can also give you a chance to receive XL Candy.
• Converting regular Candy to XL Candy at a rate of x100 Candy for x1 XL Candy, which is not very efficient but can be useful if you have a lot of Candy piling up from common spawns.

The fastest way to get XL Candy is to catch Pokemon, as catching a Pokemon will normally yield one to three pieces of Candy, and the higher level a Pokemon is, the more likely it is to drop an XL Candy.

In summary, XL Candy is a resource that allows you to level up your Pokemon beyond level 40, and you can obtain it through various methods such as catching Pokemon, hatching eggs, and transferring Pokemon.