What exactly changes when you purify a Shadow Pokemon?

Each of its three IVs (Attack, Defense, Stamina) increases by 2, capped at 15. Its Shadow combat multipliers (about ×1.2 Attack / ×0.83 Defense) are removed. Its level does not change.

Does purifying increase a Pokemon's level?

No - that's a common myth. Purification only changes the three IVs; level stays exactly the same.

How much does purifying cost?

Stardust and Candy, tiered by rarity: roughly 1,000/1 for common species up to 20,000/20 for Legendaries. Afterward, future power-ups cost 10% less than normal.

Should I purify or keep a Pokemon Shadow?

Keep high-IV, high-DPS raid attackers Shadow for the Attack bonus. Purify low-IV Pokemon, defensive Pokemon, and anything a Special Research task requires - see the best-Pokemon-to-purify guide for specifics.

Is purification reversible?

No - once purified, a Pokemon cannot be turned back into a Shadow Pokemon.

Does a Purified Pokemon's CP always go up?

Usually, but not always. If its Shadow IVs were already all 15, purifying can't raise them further, so CP stays the same (the calculator will show +0). The gain is largest when the starting IVs are low.

Pokemon GO Purify Calculator - Shadow vs Purified CP Instantly

Pick your Shadow Pokémon to see its exact current CP next to its Purified CP - computed from the real +2 IV purify mechanic, not an estimate.

What Purification Actually Does

Real Purify Calculator result comparing Shadow Dialga (3880 CP) to its Purified form (3943 CP) — An actual result from this calculator: Shadow Dialga gaining 63 CP from purification.

Shadow Pokémon come from Team GO Rocket - defeat a grunt, leader, or a Shadow raid boss, and you have a chance to catch the Shadow Pokémon left behind. They're corrupted versions of the normal species: same base stats, but with combat multipliers applied in battle (roughly ×1.2 Attack and ×0.83 Defense) and a moveset restricted to Frustration as their only Charged Move until purified.

Purifying does three things, and only three things: each of its IVs (Attack, Defense, Stamina) goes up by 2, capped at 15; its Shadow combat multipliers are removed, returning it to normal 1× stats; and it automatically learns the Purified-exclusive Charged Move, Return, replacing Frustration. Its level does not change - a common myth is that purifying bumps a Pokémon to level 25. It doesn't. What the calculator above shows is the real math: same level, same normal-form base stats, only the IVs move.

The Purify CP Formula

Purified IV = min(15, Shadow IV + 2) — for Attack, Defense, and Stamina

CP = floor( √Stamina × Attack × √Defense / 10 )

using the normal form's base stats, the purified IVs above, and the CP multiplier for the current level

This is exactly the formula the calculator above runs - the same CP formula Pokémon GO itself uses, just with base stats swapped to the normal form and IVs raised by 2 each. For example, a Shadow Snorlax at level 30 with 10/10/10 IVs sits at 2,641 CP. Purify it and its IVs become 12/12/12 (80%), pushing it to 2,690 CP - a real gain, computed exactly, not estimated.

How to Get a Shadow Pokémon

Shadow Pokémon come from three sources: defeating Team GO Rocket grunts (found at PokéStops with a purple/dark marker), defeating one of the three Team GO Rocket Leaders or Giovanni, or winning a Shadow raid. Each encounter has a chance - not a guarantee - of leaving behind a catchable Shadow Pokémon once you win the battle.

Which species you can get depends on which grunt or leader you're facing - each has a fixed lineup of possible Pokémon by type, and leaders rotate a mix of common and rarer species. Shadow raids are the only way to get Shadow Legendary Pokémon, and they run for limited windows rather than being permanently available.

What It Costs

Purifying costs Stardust and Candy up front, tiered by the species' rarity (roughly matching its Buddy walking-distance category) and flat across an entire evolution line:

1,000 Stardust / 1 Candy - common species (Zubat, Rattata, Weedle, Caterpie lines)
3,000 Stardust / 3 Candy - uncommon species (Growlithe, Psyduck, Machop, Geodude lines)
5,000 Stardust / 5 Candy - rarer species
20,000 Stardust / 20 Candy - Legendaries and similarly rare Pokémon

In exchange, every future power-up on that Pokémon costs 10% less Stardust and Candy than normal - and that discount stacks with a Lucky Pokémon's own power-up discount, down to roughly 45% of the normal cost combined.

Shadow vs. Purified, Side by Side

Staying Shadow

+ ~20% more Attack in battle
+ Often better raid/gym DPS
− ~20% more damage taken
− Locked to Frustration as a Charged Move
− Higher Stardust/Candy cost to power up

Purifying

+ +2 to every IV, capped at 15
+ Learns Return (Purified-exclusive)
+ 10% cheaper power-ups going forward
+ Normal Attack/Defense, no penalty
− Loses the Attack bonus for raids

When Purifying Is Worth It

There's no single right answer - it depends on what the Pokémon is for:

Purify: low-IV Pokémon (the +2/+2/+2 boost matters more the lower you started), defensive Pokémon (losing the Shadow Defense penalty helps more than keeping the Attack bonus), and anything a Special Research task requires you to purify
Keep Shadow: high-IV, meta-relevant raid attackers, where the Attack bonus outweighs the IV gain from purifying

As a rule of thumb, a Shadow Pokémon with 90%+ IVs is usually worth keeping Shadow for maximum raid damage, while anything below roughly 80% IVs benefits more from purification. Use the calculator above to check the exact numbers for your specific Pokémon rather than guessing from a general rule.

For specific species recommendations, see the Best Pokémon to Purify guide, and for the full mechanic breakdown, the Shadow Pokémon mechanics guide.

The Bottom Line

Purifying is a permanent, one-way decision with a real cost attached, so it's worth checking the actual numbers rather than guessing. Enter your Shadow Pokémon's IVs and level above, and you'll see precisely what you'd gain - or, for an already-maxed Shadow, precisely that there's nothing to gain from purifying it yet.

Pokemon GO Purify Calculator