Evolution is a process that many Pokémon go through which causes them to change into another, generally stronger species of Pokémon. The most common way for a Pokémon to evolve is by reaching a certain level, although there are other methods of evolving, including using items, trading Pokémon, or even flipping the system upside-down.
The process of evolving starts when the evolution condition is met and a screen is presented to the player saying something along the lines of “What? (Pokémon) is evolving!” with the Pokémon’s shape slowly transforming into the Pokémon it is evolving into. In most instances, while this is happening, you can cancel the evolution by pressing the B button, which will retain the Pokémon in its present state.
After a Pokémon has evolved, it is incapable of reverting back to its previous evolutionary stage—the evolution process is a permanent process. Evolved Pokémon generally have better stats, and often times they learn different moves, Abilities, or even have different types. (There is a similar process in Generation VI and VII games, Mega Evolution, which is temporary and is reverted after the battle is over.)
Many Pokémon can evolve not just once, but two times altogether, such as Charmander evolving into Charmeleon, who later evolves into Charizard. Some Pokémon have branching evolution lines, meaning they can evolve into different Pokémon under different conditions. For instance, the Pokémon Poliwhirl can evolve into Poliwrath if a Water Stone is used on it, or into Politoed if it is traded while holding the King’s Rock item.
However, one downside to evolving is that, for Pokémon that evolve from leveling up, level-up moves usually require a higher level to learn as opposed to the level its previous form would learn it at, and Pokémon that evolve from evolutionary stones often times don’t learn any new moves via leveling up after evolving, or learn very few compared to its previous form.
Methods of Evolving
Leveling Up
When a Pokémon reaches the level it evolves at—for instance, Bulbasaur reaching level 16 to evolve into Ivysaur—it will begin the evolution process after the battle ends. Even if it exceeds the level it evolves at, the evolution process will begin each time the Pokémon gains a level, so a level 17 Bulbasaur that gains a level to become level 18 will have the evolution process begin after the battle is over.
In the case of a Pokémon that evolves twice, it needs to reach its middle evolution stage first before evolving into its final evolution stage. For instance, a Bulbasaur cannot evolve directly into Venusaur, even if it is level 45; it would first evolve into Ivysaur, and then Ivysaur can evolve into Venusaur after gaining another level.
The lowest level a Pokémon can evolve at is level 7, for Caterpie into Metapod, Weedle into Kakuna, and Wurmple into either Silcoon or Beautifly.
The highest level a Pokémon needs to reach before it can evolve is level 64, which is necessary for Zweilous to evolve into Hydreigon.
There are some additional evolution methods that occur after a Pokémon has leveled up, as described above, but with additional prerequisites. Below are a few of the different methods that, in addition to requiring a level up, require whatever else is described.
Happiness (or Friendship)
Every Pokémon on your team or PC has a “happiness” or “friendship” value associated with it. This value increases as you do various things, such as walk (or run, or bike) around with your Pokémon in your party, level it up, let an NPC give it a haircut, use vitamins on it, etc.
Most caught Pokémon start with a happiness value of 70. When this value reaches 220 and when it gains a level, it will evolve if it is a Pokémon that evolves this way, such as Togepi into Togetic. The level they are at is completely irrelevant; if it evolves via happiness, it can evolve right after it levels up from level 1 to level 2. There are no level prerequisites, although since Pokémon gain happiness when they level up, it usually requires a good amount of effort to accomplish evolving a Pokémon in this way without being patient.
Time of Day
Some Pokémon evolve only during a certain time of day, whether it’s nighttime, daytime, or very rarely something else in between (such as with Dusk Lycanroc).
A “time of day” evolution may have any number of other prerequisites associated with it as well. For instance, many Pokémon that evolve during a specific time of day also require the happiness threshold to be met, such as Eevee into Espeon during the daytime or Eevee into Umbreon during the nighttime—both of these instances require the happiness threshold to be met in addition to it being the proper time of day.
Anything that evolves during a specific time of day has some other requirement, so just keep that in mind, but it is still important to be mindful of this evolution method.
Evolution Stones
There are several different evolution stones in the Pokémon games that can be used from the Bag to evolve a Pokémon immediately upon use. Sometimes these stones are easy to obtain, available in shops for purchase, while other times they are difficult to obtain or limited use, such as Dusk Stones or Dawn Stones. The availability of these stones varies based on game.
These stones usually correspond to an element and are used to evolve Pokémon whose type matches that element. Each of these stones are single-use items, so they are consumed upon using them to evolve the Pokémon.
Fire Stone
The following Pokémon evolve when a Fire Stone is used on them:
- Vulpix evolves into Ninetales
- Growlithe evolves into Arcanine
- Eevee evolves into Flareon
- Pansear evolves into Simisear
Water Stone
The following Pokémon evolve when a Water Stone is used on them:
- Poliwhirl evolves into Poliwrath
- Shellder evolves into Cloyster
- Staryu evolves into Starmie
- Eevee evolves into Vaporeon
- Lombre evolves into Ludicolo
- Panpour evolves into Simipour
Thunder Stone
The following Pokémon evolve when a Thunder Stone (also spelled as the “ThunderStone” without any spaces in older games) is used on them:
- Pikachu evolves into Raichu (outside of the Alola region)
- Pikachu with special forms, such as Cosplay Pikachu, Partner Pikachu, or any Pikachu wearing a hat cannot evolve.
- Pikachu evolves into Alolan Raichu (in the Alola region)
- Magneton into Magnezone only in Generation VIII and beyond
- Eevee evolves into Jolteon
- Eelektrik into Eelektross
- Charjabug into Vikavolt only in Generation VIII and beyond
Leaf Stone
The following Pokémon evolve when a Leaf Stone is used on them:
- Gloom into Vileplume
- Weepinbell into Victreebel
- Exeggcute into Exeggutor (outside of the Alola region)
- Exeggcute into Alolan Exeggutor (in the Alola region)
- Eevee into Leafeon only in Generation VIII and beyond
- Nuzleaf into Shiftry
- Pansage into Simisage
Moon Stone
The following Pokémon evolve when a Moon Stone is used on them:
- Nidorina into Nidoqueen
- Nidorino into Nidoking
- Clefairy into Clefable
- Jigglypuff into Wigglytuff
- Skitty into Delcatty
- Munna into Musharna
Sun Stone
The Sun Stone was introduced in Generation II as a prize for the Bug Catching Contest. The following Pokémon evolve when a Sun Stone is used on them:
- Sunkern into Sunflora
- Gloom into Bellossom
- Cottonee into Whimsicott
- Petilil into Lilligant
- Helioptile into Heliolisk
Dusk Stone
The Dusk Stone was introduced in Generation IV and is fairly rare to acquire. The following Pokémon evolve when a Dusk Stone is used on them:
- Murkrow into Honchkrow
- Misdreavus into Mismagius
- Lampent into Chandelure
- Doublade into Aegislash
Shiny Stone
The Shiny Stone was introduced in Generation IV and is also fairly rare to acquire. The following Pokémon evolve when a Shiny Stone is used on them:
- Roselia into Roserade
- Togetic into Togekiss
- Minccino into Cinccino
- Floette into Florges
Dawn Stone
The Dawn Stone was introduced in Generation IV and is also fairly rare to acquire. It is used to evolve only specific Pokémon that also have a particular gender. The following Pokémon evolve when a Dawn Stone is used on them:
- Male Kirlia into Gallade
- Female Snorunt into Froslass
Ice Stone
The Ice Stone was introduced in Generation VII and is reasonably rare. The following Pokémon evolve when an Ice Stone is used on them:
- Alolan Sandshrew into Alolan Sandslash
- Alolan Vulpix into Alolan Ninetales
- Eevee into Glaceon only in Generation VIII and beyond
- Galarian Darumaka into Galarian Darmanitan
Trade Evolutions
Several Pokémon evolve when they’re traded to other players. Sometimes these evolutions occur without the use of any items, merely when the Pokémon is traded, although some trade evolutions require the traded Pokémon to hold a specific item in order to trigger the evolution.
It’s important to keep in mind that, when trading Pokémon to evolve them, the player you’re trading with gets the Pokémon and it evolves in their game! This means, if you’re trading with someone to help you evolve your Pokémon—in other words, you’re expecting them to trade it back after it’s evolved—make sure it’s someone that you trust, otherwise they could run off with your Pokémon and you’ll be left with only the Pokémon they traded you.
Also, keep in mind that depositing and withdrawing Pokémon to Pokémon Bank or Pokémon HOME, as well as transferring them forward via different transfer methods that allow you to migrate Pokémon across Generations, does not count as trading, so you cannot use these methods to evolve your Pokémon that evolve in this way.
Standard Trade Evolutions
The following Pokémon will evolve when they are traded, without any other requirements:
- Kadabra into Alakazam
- Machoke into Machamp
- Graveler into Golem
- Alolan Graveler into Alolan Golem
- Haunter into Gengar
- Boldore into Gigalith
- Gurdurr into Conkeldurr
- Phantump into Trevenant
- Pumpkaboo into Gourgeist (will be of the same size)
Trade Evolutions Requiring Held Items
The following Pokémon will evolve when they are traded, but only if they are holding the listed Held Item. The Held Item is consumed after the evolution).
- Poliwhirl holding the King’s Rock evolves into Politoed
- Slowpoke holding the King’s Rock evolves into Slowking
- Onix holding the Metal Coat evolves into Steelix
- Rhydon holding the Protector evolves into Rhyperior
- Seadra holding the Dragon Scale evolves into Kingdra
- Electabuzz holding the Electirizer evolves into Electivire
- Magmar holding the Magmarizer evolves into Magmortar
- Scyther holding the Metal Coat evolves into Scizor
- Porygon holding the Up-Grade evolves into Porygon2
- Porygon2 holding the Dubious Disc evolves into Porygon-Z
- In some games (generally Generation V+), Feebas holding the Prism Scale evolves into Milotic
- Dusclops holding the Reaper Cloth evolves into Dusknoir
- Clamperl holding the Deep Sea Scale evolves into Gorebyss
- Clamperl holding the Deep Sea Tooth evolves into Huntail
- Spritzee holding the Sachet evolves into Aromatisse
- Swirlix holding the Whipped Dream evolves into Slurpuff
Trade Evolutions Requiring Specific Pokémon
Two Pokémon introduced in Pokémon Black and White—Shelmet and Karrablast—evolve when they’re traded, similar to the Pokémon listed above, however what sets them apart is that they must be traded for the other in order to start the evolution. One player must trade Shelmet and the other must trade Karrablast; no other trades will result in them evolving. Both will evolve into their evolutions—Escavalier (Shelmet’s evolution) and Accelgor (Karrablast’s evolution)—after the trade.