Launched in the French market at the end of 2013, WP Rocket aims to fill this gap. Unlike the other cache plug-ins, it is a paid service with optional license renewals for new updates and support beyond the initial validity period. It first came to my attention when a post by WPMUdev mentioned it along with the heavyweights in the WordPress marketplace. The folks at WP Rocket were kind enough to provide me with a test account for review. While the plug-in performs much of the basic caching functionality automatically without any intervention by the user, there are a few unique features that it brings to the table.
Lazy Image Loading
Lazy image loading is one of those concepts that sound really awesome but is difficult to implement without additional overhead. I remember trying to implement it once without much success. WP Rocket provides us with functionality that loads images on a website on demand as the user scrolls down. This means that on an image heavy site, only those resources are downloaded that the user actually needs to see. Upon installation of WP Rocket, a simple checkbox enables this functionality:
After saving the settings if you take a look at the code for images that haven’t been loaded yet, you will see that a new HTML attribute has been added called “data-lazy-original”
Lazy image loading works like a dream. No hassles and no additional setup. Simply enable it, and forget it.
WP Rocket offers what is known as “DNS Prefetching”. Modern websites load their resources from a number of Web servers. Whether it is CDNs or third-party plug-ins, the parent HTML downloaded from the original server can be easily overshadowed by content pulled from outside. Much of the optimization of webpages focuses on streamlining the process. DNS Prefetching allows us to shave a few precious milliseconds off of the DNS lookup for these resources. In this test example, I have instructed WP Rocket to automatically resolve “s.gravatar.com”.
It’s quite an innovative feature, and one which to my knowledge is only offered by WP Rocket.
A simple drag-and-drop interface also allows you to order the loading list for optimal functionality.
Since most of the power of WP Rocket is enabled automatically with minimal intervention, all you need to do is enable the few checkboxes for almost perfect optimization. Running a Google PageSpeed insights report for example, provides the following optimized checklist:
WP Rocket hits all the right spots. From minification, to compression and browser caching, most of the important “to do” items are taken care of. Combined with impressive features such as pre-crawling websites for priming the cache as well as the pre-resolution of DNS requests, it is set to become one of the top WordPress caching plugins.