This plugin does two things: it creates the image files required by the High-DPI devices and it displays them to your visitors accordingly. Your website will look beautiful and crisp on every device! The retina images will be generated for you automatically (though you can also do it manually) and served to the retina devices. The concept of retina images for full-size images is also a very unique feature which is only provided by this plugin (which is why it became unique). Retina Methods. It supports different methods to serve the images to your visitors. Why? Depending on the theme and plugins you are using (and also the way you use images in your website), not all the methods can work. Ideally, I would recommend using the Responsive Images method, then if it doesn’t work, the PictureFill method (which covers normally most cases). Retina.js should be the fallback method. There are more methods than this with their specific options. Plug & Play. With a well-made theme and website, this plugin doesn’t require normally any specific set-up. All the defaults settings are fine. Works with multi-site and many kinds of installs. Optimized. The plugin is very fast and optimized. It doesn’t create anything in the database. Pro. When activated, the Pro version adds support for Retina for full-size, support for lazy-loading for your responsive images and various options. And it supports my work ðŸ™? Responsive Images. WP has support for Responsive Images and this plugin handles this nicely by adding the retina images in the src-set created by WordPress. The HTML for the images not handled by WP 4.4 (outside posts) will also be handled by the plugin (pick “Picturefill” method for this). The plugin also provides an option to disable the ‘Medium Large’ created by WordPress which is actually not useful (it’s a hack basically), this plugin does it better. CSS & Background Images. The plugin cannot inject CSS to handles the images added through CSS, that’s both too dangerous and potentially very incorrect. However, in its Pro version and with PictureFill, you get an option to replace the inline CSS background image by their retina equivalent. More information and tutorial available one http://meowapps.com/wp-retina-2x/. Quickstart Set your option (for instance, you probably don’t need retina images for every sizes set-up in your WP). Generate the retina images (required only the first time, then images are generated automatically). Check if it works! – if it doesn’t, read the FAQ, the tutorial, and check the forums.