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About this tool
Apply a .cube LUT to photos and video frames locally in your browser.
The Color-Grade LUT Applier bakes a 3D lookup table from a .cube file into an image or video using FFmpeg's lut3d filter, running as WebAssembly inside your browser so the footage is never uploaded. You choose the interpolation mode — tetrahedral, trilinear or nearest — and the graded result is encoded back out with H.264 video and the original audio stream copied untouched. It is for editors and photographers who want to apply a look they already own without opening an NLE.
Open Color-Grade LUT Applier on AltFTool — it loads instantly in your browser.
Choose the image or video to grade as the Source file and your .cube LUT as the Secondary file.
Pick an Interpolation mode — tetrahedral, trilinear or nearest — and press "Process locally"; the FFmpeg WebAssembly engine loads and runs the lut3d filter in your browser.
The graded result downloads automatically as altftool-color-grade-lut-applier.mp4, with H.264 video and the original audio stream copied untouched.
The same 3D LUT implementation used in professional command-line pipelines, not a browser approximation of one.
Tetrahedral, trilinear and nearest are all exposed, so you can trade accuracy against speed rather than accept a fixed default.
Only the video stream is touched, so the soundtrack comes through bit-for-bit and processing is faster.
Two: the image or video you want graded, and a .cube LUT file as the secondary input. Both stay on your machine — FFmpeg is compiled to WebAssembly and runs in the page, so nothing is uploaded to a server.
Tetrahedral for the best accuracy, which is why it is offered first and is the usual choice for final output. Trilinear is faster with slightly softer transitions between lattice points, and nearest does no interpolation at all — fastest, but it can band on gradients.
An MP4 with H.264 video, encoded via libx264, with any existing audio track copied straight through. That plays anywhere and imports cleanly into every common editor.
No. A LUT remaps colours through a fixed table, so it applies one look uniformly; it cannot respond to a shot's exposure, white balance or specific regions. Correct exposure and balance first, then use the LUT as the creative layer on top.