reSmush.it : the only free Image Optimizer & compress plugin的作者是reSmush.it，目前有100,000+个有效安装。已经Tested with 5.4.1版本的wordpress。
reSmush.it Image Optimizer allow to use free Image optimization based on reSmush.it API. reSmush.it provides image size reduction based on several advanced algorithms. The API accept JPG, PNG and GIF files up to 5MB.
This plugin includes a bulk operation to optimize all your pictures in 2 clicks ! Change your image optimization level to fit your needs !
This service is used by more than 400,000 websites on different CMS (WordPress, Drupal, Joomla, Magento, Prestashop…).
The plugin includes an option to exclude some pictures of the optimizer.
Since Aug. 2016, reSmush.it allows to optimize pictures up to 5MB, for free !
This plugin has initially been developped by Maecia Agency, Paris.