imagemin-pngquant 
pngquant imagemin plugin
Install
$ npm install --save imagemin-pngquant
Usage
const imagemin = require('imagemin');
const imageminPngquant = require('imagemin-pngquant');
imagemin(['images/*.png'], 'build/images', {use: [imageminPngquant()]}).then(() => {
console.log('Images optimized');
});
API
imageminPngquant([options])(buffer)
Returns a promise for a buffer.
options
floyd
Type: number boolean
Default: 0.5
Controls level of dithering (0 = none, 1 = full).
nofs
Type: boolean
Default: false
Disable Floyd-Steinberg dithering.
posterize
Type: number
Reduce precision of the palette by number of bits. Use when the image will be displayed on low-depth screens (e.g. 16-bit displays or compressed textures).
quality
Type: string
Instructs pngquant to use the least amount of colors required to meet or exceed the max quality. If conversion results in quality below the min quality the image won't be saved.
Min and max are numbers in range 0 (worst) to 100 (perfect), similar to JPEG.
speed
Type: number
Default: 3
Speed/quality trade-off from 1 (brute-force) to 10 (fastest). Speed 10 has
5% lower quality, but is 8 times faster than the default.
verbose
Type: boolean
Default: false
Print verbose status messages.
buffer
Type: Buffer
Buffer to optimize.
License
MIT © imagemin