LUT Cube Analyzer Free
A free, professional-grade .cube LUT analysis tool for colorists,
video editors, photographers, cinematographers,
DITs, and LUT designers. Works with any app that supports .cube files -
DaVinci Resolve, Premiere Pro, Final Cut Pro, Vegas Pro, After Effects,
Lightroom, Capture One, Avid, and more.
Drop any .cube file (17³ – 65³, up to 9 MB) and explore it across
six analysis views: interactive 3D RGB cube, per-channel tone curves, synthetic split
preview, professional video scopes, automatic LUT DNA profiling, and side-by-side
LUT comparison.
Drop your .cube LUT here
or click to browse - supports 17³ to 65³, up to 9 MB
Choose File- Points — each dot is one LUT node; colour encodes output RGB, input RGB, or a heatmap of shift magnitude
- Vectors — arrows show the direction and magnitude of each colour shift; useful for spotting systematic gamut rotations
- Lattice — wireframe connecting adjacent nodes; makes local non-linearities and grid distortions clearly visible
- Zone — filters nodes by luminance zone (Shadows / Midtones / Highlights) to isolate analysis to a specific tonal range
- Point Size — adjusts node dot size (1–6 px) for readability at any LUT resolution
- Blend Identity — crossfades the LUT toward the identity cube (0% = full LUT effect, 100% = no change); useful for gauging transformation intensity
- Clip Overlay — highlights nodes whose output falls outside the 0–1 legal range in red
- Auto-Rotate — continuous orbit animation for a full 360° inspection
Drag to orbit · scroll to zoom · real-time WebGL rendering in-browser
- Individual R / G / B panels isolate per-channel behaviour — useful for spotting colour casts in specific tonal zones
- All Channels Overlay superimposes all three curves on one canvas for a rapid contrast and white-balance read
- Hover anywhere on a curve to read the exact input → output value and the Δ delta from neutral for each channel
- Show Identity Diagonal — reference line where input equals output (no change); use it as a baseline to judge lift or compression
- Grid — toggles a 10×10 background grid for easier visual measurement
- IRE Markers — dashed lines at Rec.709 legal black (7.3%), midtone reference (64%), and legal white (92.1%); useful when grading for broadcast delivery
- Clip Zones — shaded bands at the top and bottom 2% where output values are likely to clip
Curves are derived from a neutral-axis sweep (R = G = B = input) — accurate for tonal mapping; full-gamut saturation behaviour is visible in the Scopes tab
RGB Channel Curves — Input (x) vs Output (y)
Red
Green
Blue
All Channels Overlay
- Upload Image — load a JPEG, PNG, or WebP file (up to 20 MB); the LUT is applied entirely in-browser; the image is never transmitted or stored
- Hue Matrix — always-on synthetic base; hue sweeps the full 0–360° spectrum horizontally while saturation and brightness vary vertically; exposes hue rotation, colour shifts, and cross-channel contamination at a glance
- Grey Ramp (toggle) — 21 neutral steps from black to white; any colour cast or uneven tonal response is immediately visible on a neutral input
- Skin Tones (toggle) — 8 skin-tone patches from fair to dark; essential for portrait and documentary LUT evaluation
- Banding Test (toggle) — 64 fine steps each in the shadow (0–25%) and highlight (75–100%) zones; reveals posterisation and banding artefacts
- Split drag — drag the centre divider to compare any proportion of original vs processed output; current split percentage shown below
Synthetic layers are generated in sRGB / Rec.709. Wide-gamut or log-input LUTs should also be evaluated in the Scopes tab for full-range accuracy
Preview — before / after LUT
Split: 50%
- Waveform — output level (0–100%) vs input value; use RGB Parade for per-channel lift/gain/gamma, Luma for a combined luminance trace, or Overlay to superimpose all three channels
- Vectorscope — chroma angle and saturation in Cb/Cr space; toggle 75% / 100% to scale the colour-bar target boxes; tight cluster near centre = low saturation, long radial axis = strong hue bias
- Histogram — value distribution per channel; switch between RGB and Luma modes; enable Log Scale to reveal detail in low-count bins
- CIE xy Chromaticity — output plotted on the 1931 CIE diagram; dashed triangle = sRGB gamut; red points = clipped out-of-range values
- Saturation Response — input chroma vs output chroma scatter; points above the diagonal = saturation boost, below = reduction; coloured by input hue to show which colour families are most affected
All scopes use a phosphor-density renderer (P50 median normalisation) — brighter areas indicate higher point density
Professional Scopes — based on LUT transform of a synthetic test signal
Waveform (RGB Parade)
Vectorscope
CIE xy Chromaticity
Points coloured by output RGB · dashed = sRGB gamut · Red = clipped
Histogram
Saturation Response
Input chroma vs output chroma · diagonal = no change · above = boost · below = reduce
- Tag pills — colour-coded labels auto-generated from the analysis (e.g. Warm, Lifted Shadows, Film Emulation, Strong LUT); give an instant fingerprint
- Radar chart — six axes scored 0–100: Strength, Contrast, Saturation, Warmth, Green Push, Smoothness
- Key metric tiles — six numerical readouts (Overall Strength, Contrast, Saturation, Colour Temp, Shadow Lift, Smoothness) with contextual colour coding
- Channel × Zone table — R/G/B average delta from identity across Shadows, Midtones, and Highlights; reveals selective grading and tonal imbalances
- LUT Character — plain-language summary generated from the metrics (e.g. "Warm, lifted shadows, gentle highlight roll-off. Best suited for outdoor footage.")
- Warnings — flags highlight clipping (>1.0), shadow crushing (<0.0), near-blocked shadows, and overly strong LUT strength with opacity advice
Export the full DNA report as a PNG for documentation or LUT library cataloguing
Automatic LUT Analysis — mathematical characterisation of this LUT's behaviour
LUT Character
- Side-by-Side / Overlay Mode — view RGB curves on separate canvases or superimposed on a single canvas (LUT A solid, LUT B dashed) for direct visual comparison
- Hover tooltip — move over any curve canvas to inspect the input value, R/G/B output, and per-channel delta at that point
- Similarity Score — luma-weighted perceptual distance sampled at 33³ = 35,937 grid points; 100% = identical, lower = more divergent, with a plain-language qualifier (e.g. "Very similar — same base grade, different strength")
- Delta Analysis — R/G/B mean absolute error across the full 3D gamut, displayed as bars on a fixed 20% scale for cross-LUT comparability
- Difference Curve — A−B per channel along the neutral axis (R = G = B); auto-scaled to the actual peak delta so subtle differences remain visible
- Swap A⇔B — reverse the comparison direction without reloading files
Both LUTs must be standard .cube format. LUT A is set from the current LUT automatically; Overlay Mode and Swap activate once LUT B is loaded. Export the full comparison as PNG.
Compare two .cube LUTs — tone curves, full-gamut delta & similarity score
LUT A — current LUT
LUT B —
Drop second .cube LUT here
Delta Analysis — full-gamut mean absolute error per channel
Difference Curve (A − B) — per channel along the neutral axis (R = G = B)
Application Tips
Practical guidance generated from this LUT's DNA analysis.