The load low source image first plugin does just that: it replaces the source of every image on the page with a 1 pixel image, s.png, and creates an attribute, highsrc, with the original source url. Finally, a jquery script is loaded that shows the original image, after the page has been loaded. Instead of using this plugin, it is of course possible to use optimized images, or progressive jpeg. But not every WordPress user is familiar with those concepts. The end user does not always comply with best practices, and inserts a heavy weight image instead, with slow websites as a result. Filters llsif_replace_images: to filter the buffer including the replaced images llsif_set_imagefile : to change the default s.png image, just replace the path to s.png with your desired path. Remarks This plugin does not create a fallback for people who have javascript disabled If your site already uses lazy loading scripts, this plugin might create conflicts. If you use a theme you didn’t develop yourself and don’t know what scripts are included, test the plugin first! For more information: go to the website
