VTF is a file extension used by developer tools working with a 3D game engine called Source. VTF is a format specially developed for this engine. Such a file stores textures used in video games. VTF files are files resulting from the compilation of VMT files.

These tools were used in the production of such game titles as Half-Life 2, Dota 2, Team Fortress 2, Left 4 Dead, Portal.