Which game engine powers Cyberpunk 2077?

Cyberpunk 2077 uses CD Projekt Red’s REDengine 4.

REDengine is the proprietary technology developed by CD Projekt Red for its role-playing games. The studio used earlier versions for The Witcher series before developing REDengine 4 for Cyberpunk 2077. The engine supports the game’s large open world, branching dialogue, cinematic scenes, vehicles, crowds, and first-person gameplay.

REDengine 4 is sometimes confused with REDengine 3, which powered The Witcher 3: Wild Hunt. It is also distinct from Unreal Engine, the technology CD Projekt Red later selected for future projects through a strategic partnership with Epic Games. Cyberpunk 2077’s original release therefore belongs to the REDengine era of the studio’s development history.