difference My settings, optimization 218,274 bytes My settings, no optimization 259,852 bytes 19.05% Photoshop CC, optimization 260,305 bytes 19.28% Photoshop CC, no optimization 299,710 bytes 35.26% CodeIgniter / ExpressionEngine 340,461 bytes 55.98% TYPO3.CMS* 359,112 bytes 64.52% basic `-resize` / WordPress* 385,795 bytes 76.75% Drupal* 397,588 bytes 82.15% Perch* 416,790 bytes 90.95% Craft CMS* 425,259 bytes 94.83% grunt-responsive-images* 500,273 bytes 129.20%