Gastly evolves into Haunter starting at level 25 in the mainline Pokémon games.

Quick Scoop: When does Gastly evolve?

  • Gastly → Haunter : Levels up and evolves at level 25 in the core series games (including recent titles like Scarlet & Violet and the Switch remakes).
  • Haunter → Gengar : Typically evolves when traded between players; in some modern games there are alternate methods, but trading is the classic requirement.

So if you’re training a Gastly, just keep battling until it hits level 25 and it will try to evolve into Haunter right after the level-up screen.

Mini breakdown

  • Target level to remember: 25 for Gastly’s first evolution.
  • Make sure to let the evolution proceed (don’t cancel it) if you want Haunter right away.
  • To complete the line and get Gengar, arrange a trade once you have Haunter.

SEO notes

  • Focus phrases used: “when does gastly evolve”, “latest news” (re: modern games keeping level 25), and “forum discussion” style breakdown based on current game data.
  • Meta description style: Gastly evolves into Haunter at level 25, then into Gengar by trading Haunter, consistent across modern Pokémon titles as of 2026.

TL;DR : Gastly evolves at level 25 into Haunter, and Haunter evolves into Gengar when traded.

Information gathered from public forums or data available on the internet and portrayed here.