NG-Lazyload plugin replaces all the thumbails and images in the content with the smallest image possible (1 pixel gif) and then shows the full image only when it is in viewport.
The only plugin which also works with background images in style tag
Use WordPress' Add New Plugin feature, searching "NG-Lazyload", or download the archive and:
- Unzip the archive on your computer
- Upload plugin directory to the
/wp-content/plugins/
directory
- Activate the plugin through the 'Plugins' menu in WordPress
- No more actions required
For theme developers: add nglazyload class to html blocks with background images
to lazy-load them if they are stated in css file.
If html block has style="background-image: url(...)" you don't have to.