LUT Previewer

Knowledge Base

What a .cube LUT Actually Is

A .cube file is a 3D lookup table: a grid of pre-computed output colors for a fixed number of input color combinations (commonly 17×17×17 or 33×33×33). To grade a real pixel that falls between grid points, a proper LUT engine has to interpolate between the eight nearest grid corners. This tool does that trilinear interpolation for real, the same math a color grading application uses, rather than faking the look with a CSS filter.

Why Intensity Control Matters

Many creative LUTs are designed to be applied at less than 100% strength, blended with the original image to taste. The intensity slider linearly blends between your untouched upload and the fully-graded result, which is exactly how "LUT opacity" works inside a real NLE or grading tool.

Where to Get .cube Files

Camera manufacturers (Sony, Panasonic, Blackmagic, RED) publish free log-to-Rec.709 conversion LUTs for their cameras, and many colorists release free creative LUT packs, search "[your camera model] LUT download" or "free cinematic LUT pack .cube" to find some to try here.

FAQ

Q: Does this support 1D LUTs?
A: No. This tool reads 3D LUTs only (the `LUT_3D_SIZE` format most creative and camera LUTs use). A 1D-only .cube file will show an error.

Q: My image looks wrong after applying the LUT, why?
A: Most creative LUTs expect Rec.709/sRGB footage as input. If your source is log or RAW footage viewed without its own conversion first, the LUT's math will be applied to the wrong starting point and the result will look off, convert to Rec.709 first, or use the camera manufacturer's log-to-709 LUT before a creative look LUT.