Image Color Quantizer 🎨

About the Image Color Quantizer

The Image Color Quantizer runs entirely in your browser. Drop or select an image, set Colors per channel between 2 and 8, and click Apply. Each RGB channel is remapped to a fixed number of evenly spaced values using integer division. The step size is computed as n = round(255 / (levels − 1)), then every channel value is transformed with round(value / n) × n and clamped to 0–255. The total number of distinct colors in the output is levels³ — for example, 2 levels yield 8 colors, 4 levels yield 64 colors, and 8 levels yield 512 colors. Lower values produce a flat, poster-like look with bold blocks of color; higher values approach the original image. Nothing is uploaded; all processing happens locally.

How to use it

1. Click the drop zone or drop an image file onto it.
2. Drag the Colors per channel slider — lower values mean fewer colors and a more dramatic effect. The total color count updates in real time.
3. Click Apply to render the effect onto the image.
4. Click Download to save the result, Reset to restore the original, or Clear to start over.

Frequently asked questions

What does "colors per channel" mean? It is the number of distinct values each RGB channel can take after quantization. The total number of colors is the cube of this value: 2 → 8, 3 → 27, 4 → 64, 5 → 125, 6 → 216, 7 → 343, 8 → 512.

What is the output format? The download is a PNG file. This preserves detail and avoids compression artifacts.

Does this tool upload my images? No. All processing happens locally in your browser. Your image never leaves your device.

Can I apply the effect multiple times? Yes. Each Apply works on the current canvas, so successive clicks compound the effect. Use Reset to return to the original.