IntegerScaler is a free utility for upscaling windowed games with an integer ratio and with no blur. Such scaling is known as integer (integer-ratio, integer-factor, integral) scaling, pixel-perfect scaling, and pixel doubling.

This allows playing games with no quality loss e. g. at Full-HD (1920×1080) resolution on 4K (3840×2160) monitors, unlike ever-blurry bilinear interpolation used for full-screen scaling by displays and graphics drivers.