Free tool · nothing is uploaded
HALD ↔ CUBE
A LUT stored as a picture, and a LUT stored as a file. Drop either one and the tool works out which way you are going.
Drop a HALD .png or a .cube
- .png
- .cube
The direction is chosen from the file you drop. Read and converted on your own device; nothing is uploaded.
drop, click, or paste
No HALD to hand?
Download the identity image, open it in any editor, apply a grade to it and save. The result is that grade as a LUT — which is how you get a LUT out of software that has no LUT export, meaning most photo editors.
A colour cube folded into a square
A HALD CLUT is a 3D LUT with the numbers written as pixels instead of as text. Each pixel holds one entry of the cube — its colour is the output value — laid out row by row across a square image. Nothing else about it is special: it is an ordinary PNG, and that is the whole point, because it means any image editor can open, change and save a LUT without knowing what a LUT is.
| Level | Image | Cube | Entries |
|---|---|---|---|
| 4 | 64 × 64 | 16³ | 4,096 |
| 6 | 216 × 216 | 36³ | 46,656 |
| 8 | 512 × 512 | 64³ | 262,144 |
The sizes are not arbitrary and cannot be chosen freely. The image has to be square, so side² = size³, which has an integer answer only when the grid size is itself a perfect square. That is why 17³, 33³ and 65³ — the three sizes every other tool on this site treats as standard — cannot be written as a HALD at all, and why a 33³ going out comes back as 36³.
Getting a LUT out of an editor that has no LUT export
This is the trick HALD is genuinely good for, and it works in any editor that can open a PNG. Download the identity image above, apply your grade to it exactly as you would to a photograph, and save it. Drop the result back here and you have that grade as a .cube.
It works because the identity HALD contains every colour in the cube exactly once, in a known order. Whatever the editor does to those pixels is the transform, read straight back out. The one rule: no cropping, no resizing, no JPEG — the image is data, and any operation that moves pixels around destroys it.
Next steps
- Check what the LUT does — worth doing after a HALD round trip, since 8-bit quantisation is real even when it is invisible.
- Measure the round-trip cost — compare the original against the converted one and get the difference as a number rather than a guess.
- Make a LUT from a Lightroom preset — the other direction into the same format.
- Resize a LUT — to get from a HALD-native size back to the 17³, 33³ or 65³ a device expects.
Frequently asked questions
What is a HALD CLUT?
A 3D LUT stored as an ordinary image. Every pixel is one entry in the colour cube, laid out so the file can be opened, edited and saved by any image editor. It is how the open-source colour tools distribute LUTs — G'MIC, RawTherapee and darktable all use it — and it is why those packs will not load in Resolve or Premiere without converting first.
Why is the image always square, and why those specific sizes?
Because the cube has to fit a square exactly. A HALD of level L holds a cube of side L² in an image of side L³ — level 8 is a 64³ cube in 512×512, since 512² is 262,144 and so is 64³. That only works when the grid size is a perfect square, which is why the sizes on offer are 4³, 9³, 16³, 25³, 36³, 49³ and 64³ rather than the usual 17, 33 and 65.
My 33³ LUT came out as 36³. Why?
Because 33³ cannot be a HALD. 33 is not a perfect square, so there is no square image with exactly 35,937 pixels. The tool resamples to the nearest size that works and tells you it did. The transform is the same; the lattice it is sampled on is slightly finer.
Is anything lost converting to HALD?
Precision, a little. A HALD is a PNG and a PNG channel is a byte, so values are quantised to 8 bits — a round trip is accurate to half a step out of 255. For a creative look that is far below anything visible. For a technical transform with very steep behaviour it is worth checking with the comparison tool rather than assuming.
How do I make a LUT from an editor that cannot export one?
Download the identity HALD from this page, open it in the editor, apply your grade to it and save it as a PNG. Drop the result back here and you have the same grade as a .cube. It works because the identity image contains every colour exactly once — whatever the editor does to those pixels is, by definition, the LUT.
Can I use a JPEG?
You can drop one and it will probably decode, but do not. JPEG is lossy and a HALD is data rather than a picture — the compression smears neighbouring entries into each other, which in a LUT means colours bleeding into colours that are nowhere near them on screen. Always save a HALD as PNG.
Is my file uploaded?
No. The image is decoded with the browser's own canvas and converted on your device. Nothing is transmitted and there is no account.
A LUT tells you nothing about how it was built.
That is the trade you accept when you bake one: thirty-five thousand answers and no record of the question. The Studio works the other way round — give it a photograph and its recipe and it shows the edit as a sequence of decisions, each one rendered on its own.