Q&A for How to Evolve Onix

You can mega-evolve Steelix into Mega Steelix by using a Mega Ring, a Key Stone, and Steelixite.

Onix's evolution, Steelix, was not introduced until Generation II. The Pokémon Let's Go Pikachu and Let's Go, Eevee games only feature the original 151 Pokémon, along with Meltan, Melmetal, and a few Alolan forms.

To evolve Onix into Steelix, you must trade it while it holds a Metal Coat. This process typically requires a trading cable, so you cannot evolve it without one in games where cables are necessary for trading.

No, Onix does not have a pre-evolved form. You'll find it is the first Pokémon in its evolutionary line.

Many Pokémon game ROMs are modified so that trade evolutions work through different means, such as leveling up. Alternatively, you might use a cheat code.

Unfortunately, trading between players on an emulator is not possible. However, most emulators include level-up evolutions for Pokémon that were originally trade evolutions.