myTask: { options: { sizes: [{ width: 320, height: 240 },{ name: 'large', width: 640 },{ name: "large", width: 1024, suffix: "_x2", quality: 60 }] }, files: [{ expand: true, src: ['assets/**.{jpg,gif,png}'], cwd: 'test/', dest: 'resize/{%= width %}/' }] } }, }); Sample grunt-responsive-images configuration