andrewmoof

DNS resolution time can lead to a significant amount of user perceived latency. The time that DNS resolution takes is highly variable. Latency delays range from around 1ms (locally cached results) to commonly reported times of several seconds.
DNS prefetching is an attempt to resolve domain names before a user tries to follow a link. This is done using the computer’s normal DNS resolution mechanism. Once a domain name has been resolved, if the user does navigate to that domain, there will be no effective delay due to DNS resolution time. When we encounter hyperlinks in pages, we extract the domain name from each one and resolving each domain to an IP address. All this work is done in parallel with the user’s reading of the page, using minimal CPU and network resources. When a user clicks on any of these pre-resolved names, they will on average save about 200 milliseconds in their navigation (assuming the user hadn’t already visited the domain recently). More importantly than the average savings, users won’t tend to experience the “worst case” delays for DNS resolution, which are regularly over 1 second.

Simple DNS Prefetch

Adds (or removes) DNS prefetching meta tags to your site and speeds up your page load speed.

Stanislav Khromov

titanas

Instant Articles for WordPress will let you configure DNS prefetching URLs and will automatically prerender the last 2 posts on the front page, plus next and previous posts when viewing a single post. You also have the option to pre-render sticky posts.
It is not recommended to use more than 4-5 URLs for DNS prefetching.
Enabling page prerendering will likely increase server and client (browsers) load.
Enabling subresources will let you specify URL’s to hint the web browser for high priority files, likes .JS or .CSS, for fetching these even before they appear in the HTML document.
Visit the Instant Articles homepage for more info: http://wpinstant.io/
Usage
Basic usage
Install plugin, go to the WP Admin > Instant Articles screen and enable the features you want.
<h3>Requirements</h3>
<ul>
<li>PHP version 5.2.4 or greater</li>
</ul>
<h3>Translations</h3>
<ul>
<li>None</li>
</ul>

WordPress Instant Articles

WordPress Instant Articles dramatically improves user experience and site speed with page pre-render, DNS prefetch, Link Prefetch, HTML5 subresource

Simple DNS Prefetch vs WordPress Instant Articles