Download speed is a huge SEO variable. Here are plugins you can use to make your website faster and improve your SEO and rankings. Content delivery network (CDN) and caching plugins improve your download speed and so do plugins which optimize file size for downloads. Don't worry, you don't have to understand CDN or cache to take advantage of these plugins. Download speed is a huge SEO variable. There is just one SEO plugin we recommend (can you guess?) and so , too for linking your website with Google Analytics. This is our 3rd of 4 episodes on WordPress plugins.