Free tool · no account
CUBE viewer
Drop a .cube LUT and see what it actually does — the tone curve hiding inside it, the cast it puts on neutrals, where it moves hues, and how it looks on a real frame.
Drop a .cube LUT here
Parsed in your browser — the file is never uploaded. Works with Adobe, Resolve and camera-monitor LUTs.
Reading the plots
A 3D LUT is tens of thousands of numbers, which is why they are usually treated as black boxes you either like or don’t. But almost everything worth knowing about one is captured by three one-dimensional slices through it.
Neutral axis
Feed the LUT pure grey and watch what comes out. The luma line is the tone curve; channel separation is the colour cast.
Per-channel transfer
Each primary ramped on its own — the closest 3D-LUT analogue of Lightroom's per-channel tone curves.
Hue shifts
Sampled where memory colours live — skin, sky, foliage — so you can see which hues the LUT actually moves.
Frequently asked questions
How do I open a .cube file without Photoshop or Resolve?
Drop it here. A .cube file is plain text describing a 3D colour lookup table, and this page parses it in your browser — no editing software, no account and no upload required.
What is the neutral-axis response curve?
It is what the LUT does to a pure grey ramp. The white line is tone: its steepness is contrast, so a line that bows above the diagonal is lifting your image and one that steepens through the middle is adding contrast. Where the red, green and blue lines separate from each other, the LUT is tinting neutral greys — and that separation is precisely what people mean when they say a LUT 'feels teal' or 'feels warm'.
Why does the same LUT look different on my footage?
Most creative LUTs assume a specific input — a log profile like S-Log3 or V-Log, or already-corrected Rec.709. Feeding a LUT an input it was not built for is the single most common reason a look that appeared fine in a preview turns muddy or over-contrasted on real footage. Check what the LUT expects before blaming the LUT.
Can I preview the LUT on my own photo?
Yes. The preview loads a sample frame by default, but you can swap in any JPEG, PNG or WebP from your own machine. It is rendered through the same WebGL pipeline RawCut uses everywhere else, so the preview and the plotted analysis describe the same transform.
What LUT sizes are supported?
Any 3D LUT from 2×2×2 up to 65×65×65, which covers everything Adobe, DaVinci Resolve, camera monitors and LUT vendors produce. 1D LUTs are a different format and are not supported — they only remap tone per channel and carry no colour cross-talk.
Does the tool modify or upload my LUT?
No. The file is read locally with the browser's File API and never leaves your device. Nothing is written back, so your original file is untouched.