best image compression settings (gulp-imagemin)

gulpfile.js

// install
// npm i gulp-cache gulp-imagemin imagemin-pngquant imagemin-zopfli imagemin-mozjpeg imagemin-giflossy -f
// node node_modules/jpegtran-bin/lib/install.js
// node node_modules/gifsicle/lib/install.js
// node node_modules/zopflipng-bin/lib/install.js
// node node_modules/mozjpeg/lib/install.js
// node node_modules/giflossy/lib/install.js
// node node_modules/pngquant-bin/lib/install.js


var cache = require('gulp-cache');
var imagemin = require('gulp-imagemin');
var imageminPngquant = require('imagemin-pngquant');
var imageminZopfli = require('imagemin-zopfli');
var imageminMozjpeg = require('imagemin-mozjpeg'); //need to run 'brew install libpng'
var imageminGiflossy = require('imagemin-giflossy');

//compress all images
gulp.task('imagemin', function() {
    return gulp.src(['app/**/*.{gif,png,jpg}'])
        .pipe(cache(imagemin([
            //png
            imageminPngquant({
                speed: 1,
                quality: [0.95, 1] //lossy settings
            }),
            imageminZopfli({
                more: true
                // iterations: 50 // very slow but more effective
            }),
            //gif
            // imagemin.gifsicle({
            //     interlaced: true,
            //     optimizationLevel: 3
            // }),
            //gif very light lossy, use only one of gifsicle or Giflossy
            imageminGiflossy({
                optimizationLevel: 3,
                optimize: 3, //keep-empty: Preserve empty transparent frames
                lossy: 2
            }),
            //svg
            imagemin.svgo({
                plugins: [{
                    removeViewBox: false
                }]
            }),
            //jpg lossless
            imagemin.jpegtran({
                progressive: true
            }),
            //jpg very light lossy, use vs jpegtran
            imageminMozjpeg({
                quality: 90
            })
        ])))
        .pipe(gulp.dest('dist'));
});

Had already compressed JPEG and PNG images using online image compressing and optimising tools.
But thought to gave this script a shot. Results: Compressed PNG by further 855B whereas interestingly increase JPEG size by 22KB (348KB -> 370KB). But overall, a good minification script 👍

In imagemin 7.1.0 now use

imagemin.mozjpeg({
                progressive: true
}),

this is an outdated option

imagemin.jpegtran({
     progressive: true
}),

@GKoil how is it possible??? How they can change lossless method to loss by default???

work for me

const gulp = require('gulp');
const imagemin = require('gulp-imagemin');
var cache = require('gulp-cache');
var imageminPngquant = require('imagemin-pngquant');
var imageminZopfli = require('imagemin-zopfli');
var imageminMozjpeg = require('imagemin-mozjpeg'); //need to run 'brew install libpng'
var imageminGiflossy = require('imagemin-giflossy');
function optimizeImages(done){
gulp.src('resources/assets/images/*')
.pipe(imagemin({
interlaced: true,
progressive: true,
optimizationLevel: 5
}))
.pipe(cache(imagemin([
//png
imageminPngquant({
speed: 1,
quality: [0.95, 1] //lossy settings
}),
imageminZopfli({
more: true
// iterations: 50 // very slow but more effective
}),
//gif
// imagemin.gifsicle({
// interlaced: true,
// optimizationLevel: 3
// }),
//gif very light lossy, use only one of gifsicle or Giflossy
imageminGiflossy({
optimizationLevel: 3,
optimize: 3, //keep-empty: Preserve empty transparent frames
lossy: 2
}),
//svg
imagemin.svgo({
plugins: [{
removeViewBox: false
}]
}),
//jpg lossless
imagemin.mozjpeg({
progressive: true
}),
//jpg very light lossy, use vs jpegtran
imageminMozjpeg({
quality: 90
})
])))
.pipe(gulp.dest('public/images'))
done();
}
var resourcesOptimization = gulp.series(optimizeImages);
gulp.task('build', resourcesOptimization);
gulp.task('default', resourcesOptimization);

Thanks