Color Palette from Photo is 100% client-side. When you drop, browse or paste an image it is loaded into an in-memory HTML5 <canvas>; the tool reads its RGBA pixels with getImageData and runs the whole colour-quantization and eyedropper logic in the page. No bytes are sent to a server, there is no upload endpoint and no CDN in the processing path, and nothing is logged or stored. The tool works offline once cached, keeps no accounts and sets no tracking, and the image and palette are discarded the moment you close the tab.

The pixels are quantized with a Bloomberg/Leptonica-style modified median cut. The full set of sampled colours is treated as one box in RGB space; the engine repeatedly splits the box along its widest colour axis at the median, but it always picks the box with the greatest priority — its colour-cube volume multiplied by how many pixels it holds. Weighting by population (rather than just colour range, as plain median cut does) keeps small but distinct clusters — a logo, a bright accent — from being merged into one huge near-uniform region such as a sky. Each final box’s swatch is its population-weighted average colour, and its share of the sampled pixels is reported as a percentage.

A palette is a summary: every swatch is the population-weighted average of a cluster of similar pixels, so it represents a range of the image rather than any single pixel — that is why a subtle accent can be masked by a large near-uniform region. For speed the image is also sampled at a capped long side of about 360px, so the palette is a faithful approximation rather than a per-pixel census. If you need one precise colour, move over the image with the built-in eyedropper, which reads the exact pixel (averaged over a tiny 3×3 window to shrug off JPEG noise); to surface more accents in the palette, raise the colour count.

After extraction you can order the palette by dominance, hue (spectrum) or lightness, then export it several ways: a labelled PNG swatch sheet (each band shows the hex, pixel share and nearest CSS colour name), CSS custom properties (:root variables), a JSON array with hex/RGB/HSL and share, a GIMP palette (.gpl) that GIMP, Inkscape and Krita import directly, or plain HEX / RGB / HSL lists you can paste into professional design tools, Sketch or code. Every individual swatch and value is also one-tap copyable. All exports are produced locally — nothing is uploaded.