An EFT file is a settings file used by Logitech Gaming Software, a program used to customize Logitech G gaming mice, headsets, speakers, select wheels, and keyboards. It contains lighting effects information for a keyboard, which includes the device layout and colors. EFT files are often created by and shared with other gamers who use Logitech devices.

You may create a variety of effects using the Lighting Editor in Logitech Gaming Software. The effects can be simple color schemes or complex animations, such as audio waves, spinning RGB colors, a waving American flag, and a sunrise. To open an EFT file in Logitech Gaming Software, click the Settings gear icon in the Lighting Editor interface, select Import, and choose the EFT file you want to open. To create an EFT file in Logitech Gaming Software, click the Settings gear icon in the Lighting Editor interface, select Create New Effect, modify the effect, and select Export from the Settings menu.