README.md
Extract dominant colors and palettes from images in the browser and Node.js.
npm install colorthief
Or load directly from a CDN:
<script src="https://unpkg.com/colorthief@3/dist/umd/color-thief.global.js"></script>
import { getColorSync, getPaletteSync, getSwatches } from 'colorthief';
// Dominant color
const color = getColorSync(img);
color.hex(); // '#e84393'
color.css(); // 'rgb(232, 67, 147)'
color.isDark; // false
color.textColor; // '#000000'
// Palette
const palette = getPaletteSync(img, { colorCount: 6 });
palette.forEach(c => console.log(c.hex()));
// Semantic swatches (Vibrant, Muted, DarkVibrant, etc.)
const swatches = await getSwatches(img);
swatches.Vibrant?.color.hex();
observe() watches video, canvas, or img elements and emits palette updates reactivelyImageBitmap or OffscreenCanvascolorSpace: 'oklch'.hex(), .rgb(), .hsl(), .oklch(), .css(), contrast ratios, text color recommendationscolor.contrast.white, color.contrast.black, color.contrast.foregroundcolorthief photo.jpg with JSON, CSS, and ANSI output| Function | Description |
|---|---|
getColorSync(source, options?) | Dominant color (sync, browser only) |
getPaletteSync(source, options?) | Color palette (sync, browser only) |
getSwatchesSync(source, options?) | Semantic swatches (sync, browser only) |
getColor(source, options?) | Dominant color (async, browser + Node.js) |
getPalette(source, options?) | Color palette (async, browser + Node.js) |
getSwatches(source, options?) | Semantic swatches (async, browser + Node.js) |
getPaletteProgressive(source, options?) | 3-pass progressive palette (async generator) |
observe(source, options) | Watch a source and emit palette updates (browser only) |
createColor(r, g, b, population) | Build a Color object from RGB values |
| Option | Default | Description |
|---|---|---|
colorCount | 10 | Number of palette colors (2–20) |
quality | 10 | Sampling rate (1 = every pixel, 10 = every 10th) |
colorSpace | 'oklch' | Quantization space: 'rgb' or 'oklch' |
region | — | Sample a sub-rectangle: { x, y, width, height } as 0–1 fractions |
gamut | 'srgb' | Output gamut: 'srgb', 'display-p3', or 'auto' (browser only) |
worker | false | Deprecated — ignored as of v3, removed in v4. See Web Workers |
signal | — | AbortSignal to cancel extraction |
ignoreWhite | true | Skip white pixels |
| Property / Method | Returns |
|---|---|
.rgb() | { r, g, b } |
.hex() | '#ff8000' |
.hsl() | { h, s, l } |
.oklch() | { l, c, h } |
.css(format?) | 'rgb(255, 128, 0)', 'hsl(…)', or 'oklch(…)' — a P3 color's default .css() is color(display-p3 …) |
.array() | [r, g, b] |
.gamut | 'srgb' or 'display-p3' |
.toString() | Hex string (works in template literals) |
.textColor | '#ffffff' or '#000000' |
.isDark / .isLight | Boolean |
.contrast | { white, black, foreground } — WCAG ratios |
.population | Raw pixel count |
.proportion | 0–1 share of total |
Pass a region to sample only part of the image. Coordinates are fractions of
the image size (0–1) measured from the top-left, so a region is
resolution-independent — the same values work for a thumbnail and the full-size
original.
// Colors from the bottom third — e.g. for a gradient that overlaps the
// bottom of the image
const palette = await getPalette(img, {
region: { x: 0, y: 0.66, width: 1, height: 0.34 },
});
// Center crop
const color = await getColor(img, {
region: { x: 0.25, y: 0.25, width: 0.5, height: 0.5 },
});
Works everywhere an option object does: getColor, getPalette, getSwatches,
getPaletteProgressive, the *Sync functions, observe(), and the CLI — in
both browser and Node. A region that runs past the right or bottom edge is
clamped to the image; out-of-range or zero-sized values throw.
import { getColorSync, getPaletteSync } from 'colorthief';
const img = document.querySelector('img');
const color = getColorSync(img);
console.log(color.hex());
const palette = getPaletteSync(img, { colorCount: 5 });
Accepts HTMLImageElement, HTMLCanvasElement, HTMLVideoElement, ImageData, ImageBitmap, and OffscreenCanvas.
By default colors are read and reported in sRGB. For P3-tagged / wide-gamut images, pass gamut to preserve the extra saturation:
// Force P3: read the image through a P3 canvas, report P3 colors
const palette = await getPalette(img, { gamut: 'display-p3' });
palette[0].css(); // 'color(display-p3 0.92 0.2 0.14)'
palette[0].gamut; // 'display-p3'
// Auto: report P3 only when the image actually uses out-of-sRGB colors,
// otherwise behave exactly like sRGB
const auto = await getPalette(img, { gamut: 'auto' });
.rgb(), .array(), and .hex() always return sRGB (gamut-mapped when the color is P3), so existing rgb(...) strings keep working. The wide-gamut values live in .css() and .oklch(); use .rgb('display-p3') for the raw P3 components. Falls back to sRGB where P3 canvas support is unavailable. Node output is sRGB for now.
import { observe } from 'colorthief';
// Watch a video and update ambient lighting as it plays
const controller = observe(videoElement, {
throttle: 200, // ms between updates
colorCount: 5,
onChange(palette) {
updateAmbientBackground(palette);
},
});
// Stop when done
controller.stop();
Works with <video>, <canvas>, and `` elements. For images, it uses a MutationObserver to detect src changes. For video and canvas, it polls using requestAnimationFrame with throttle.
To keep extraction off the main thread, run Color Thief inside your own worker and hand it an ImageBitmap. Bitmaps are transferable, so the pixels move without being copied, and decoding, sampling, and quantization all happen off-thread.
// main.js
const bitmap = await createImageBitmap(await (await fetch(url)).blob());
const worker = new Worker('./palette-worker.js', { type: 'module' });
worker.postMessage({ bitmap }, [bitmap]); // transferred, not cloned
worker.onmessage = (e) => render(e.data.palette);
// palette-worker.js
import { getPalette } from 'colorthief';
self.onmessage = async ({ data }) => {
const palette = await getPalette(data.bitmap, { colorCount: 5 });
// Color objects don't survive structured clone — send plain data
self.postMessage({ palette: palette.map((c) => c.hex()) });
};
Deprecated: the
worker: trueoption is ignored as of v3 and will be removed in v4, along with theisWorkerSupported,extractInWorker, andterminateWorkerexports fromcolorthief/internals. It only moved quantization off-thread while leaving decoding, pixel sampling, and the structured clone of the pixel array on the main thread — and serializing that array cost several times more than the quantization it saved. It also quantized in RGB while the default path uses OKLCH, soworker: truereturned different colors. Calls that pass it now go through the normal pipeline and log a one-time warning.
import { getColor, getPalette } from 'colorthief';
const color = await getColor('/path/to/image.jpg');
console.log(color.hex());
const palette = await getPalette(Buffer.from(data), { colorCount: 5 });
Accepts file paths and Buffers. Uses sharp for image decoding.
npx colorthief-cli photo.jpg
The colorthief-cli package bundles everything needed (including sharp for image
decoding), so it works immediately with no extra setup.
# Dominant color
colorthief-cli photo.jpg
# Color palette
colorthief-cli palette photo.jpg
# Semantic swatches
colorthief-cli swatches photo.jpg
# Default: ANSI color swatches
colorthief-cli photo.jpg
# ▇▇ #e84393
# JSON with full color data
colorthief-cli photo.jpg --json
# CSS custom properties
colorthief-cli palette photo.jpg --css
# :root {
# --color-1: #e84393;
# --color-2: #6c5ce7;
# }
colorthief-cli palette photo.jpg --count 5 # Number of colors (2-20)
colorthief-cli photo.jpg --quality 1 # Sampling quality (1=best)
colorthief-cli photo.jpg --color-space rgb # Color space (rgb or oklch)
colorthief-cli photo.jpg --region 0,0.66,1,0.34 # Sample the bottom third
--region takes x,y,width,height as fractions of the image size (0–1), the
same as the region option.
Stdin is supported — use - or pipe directly:
cat photo.jpg | colorthief-cli -
Multiple files are supported. Output is prefixed with filenames, and --json wraps
results in an object keyed by filename.
Note: If you already have
colorthiefandsharpinstalled in a project, you can also usecolorthiefdirectly as the command name (without the-clisuffix).
npm run build # Build all dist formats
npm run test # Run all tests (Mocha + Cypress)
npm run test:node # Node tests only
npm run test:browser # Browser tests (requires npm run dev)
npm run dev # Start local server on port 8080
# 1. Make sure you're on master with a clean working tree
git status
# 2. Run the full test suite
npm run build
npm run test:node
npm run test:browser # requires npm run dev in another terminal
# 3. Preview what will be published
npm pack --dry-run
# 4. Tag and publish
npm version <major|minor|patch> # bumps version, creates git tag
npm publish # builds via prepublishOnly, then publishes
git push && git push --tags
MIT - Lokesh Dhakar