Let’s take a look at what we know about the methods on how to earn XL Candy
Thanks to The SilphScience Research Group we know that the higher level a Pokémon is, the more likely it is to drop a XL Candy.
Higher level also means lower catchrate, so catching manually is preferred over the Go Plus as it only throws one regular Pokeball.
Curveball, Precision (Nice, Great & Excellent), Razz / Gold Razz Berry and Great/Ultra Ball all improve the catchrate while throwing manually, plus you can keep trying until the Pokémon flees or you caught it.
The highest levels also apppear to have a higher chance of dropping multiple XL Candy
It’s seems like second and third stage evolution, don’t give any more candy, nor does using Pinaps.
Weather Boosted Pokémon gain extra level resulting in a higher yield of XL Candy.
As an example Cloudy or Windy Weather during non event days is when you can farm XL Meditite Candy.
For the biggest gains for nesting Pokémon try to go when they are weather boosted.
Current Nest Pokémon worth farming are
UL Skarmory, Clefairy, Eevee for Umbreon ML Mudkip, Swinub, Machop Mega: Gen 1 & 3 Starter, Snover
Make good use of Event Spawns, for example Chansey for Valentine’s or Sableye for Halloween
Special Lures are also an option, for example a Magnetic Lure is currently almost the only way to encounter Shieldon to get XL Candy for that Great League Bastidon.
Thanks to the global Twitter community we were able to establish that the higher level means higher chance of XL Candy also applies to transferring Pokémon. The weather boost exclusive Levels 31 to 35 had by far the highest XL Candy drop chance, making catching those high level Pokémon even more worth it. I know the old saying: All berries are for gyms, but at least use Razz or Golden Razz on those big ones with a high flee rate to maximize your XL Candy gains.
Mass Transfer or deleting one by one makes no difference
Eggs currently drop between 0 and 4 XL Candy.
Not a very reliable way to farm XL candy as you can’t control what you are hatching, but there are skme egg exclusive Pokémon like Galar Stunfisk, Vullaby and Riolu
We need more research, but it seems like the higher level, higher chance of XL seems to apply for raids as well, making it the best practice to make use of weather boost. Having friends in different parts of the world is a good idea to focus on raiding weather boosted bosses.
Not the most effective way to get XL, but it adds up.
100 Candy equal 1 XL Candy, so about 33 catches or 17, if you use Pinaps.
Also running a Mega Pokémon could be worth it to get that extra candy for each catch, e.g have a Mega Blastoite while farming a Mudkip nest
6. Field Research
At Level 15 less than 10% chance of dropping a XL Candy at catch or transfer, but if it’s a Pokémon that is otherwise rare in the wild, then doing the quest for the encounter might be worth it to earn the candy for a conversion
Shadow Pokémon are Level 8 and Level 13 weather boosted, so catching and deleting them has less than a 10% chance of dropping XL Candy.
BUT, if you purify them, they become Level 25 and have around 50% chance of dropping a XL on transfer
For example as Sableye is not nesting anymore and is very rare outside of Halloween and maybe Fog, transferring Purified Sableye seems the best way to get that XL Candy
Receiving a XL Candy from trades is currently turned off as Niantic is probably trying to fix the trade exploit. But DO save your Rares, you want XL Candy for as potential future mean to gain more XL Candy
8. Feeding Gyms
I feel like Niantic said at one point that feeding berries to a gym can reward XL Candy, but I have yet to observe it
I am a grinder, not a writer nor a native english speaker, but i hope this post will be useful for some of you.
Thanks to everyone who helped to compile this info and if you can think of anything else, please leave a comment