WP Retina 2x

This plugin creates the image files required by the Retina (high-DPI) devices and displays them to your visitors accordingly. Your website will look beautiful and sharp on every device. The retina images will be generated for you automatically (you can also do it manually), served, and you will be able to control everything from the Retina Dashboard.

Retina for all

It supports 4 different methods to serve the images to your visitors:

The Picturefill method rewrites the HTML on-the-fly in order to use the new SRCSET. Since it is not supported by the browsers yet, the JS polyfill Picturefill is used to load the images. It is now the recommended method. 
The Retina JS method is a 100% JS solution. The HTML loads the normal images, then if a retina device is detected, the retina images will be loaded. It is fail-safe but not efficient (images are loaded twice). 
The IMG Rewrite method rewrites IMG’s SRC tags on-the-fly with the retina images directly if the device supports them. This method does not work with most caching solutions.
The Retina-Images method uses a server handler: the images will be loaded through the Retina-Images PHP handler. Your .htaccess will be modified automatically.

Pick the one that works best with your hosting and environment. WordPress Multi-site are supported as well. WP Retina 2x also loves WPEngine and strongly recommend it for your hosting. I am trying to keep a tutorial about this plugin up to date and comprehensive here: http://www.totorotimes.com/wp-retina-2x-plugin/.

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.

Issues ? Questions ?

Check the FAQ and the official support forum.

Download for WordPress
The plugin for WordPress will be updated automatically when a new version is available.

I recommend you to use WPEngine (best host for WordPress) and MaxCDN (faster images loading). I use both.