The Delay JavaScript is the feature which helps improving the Reduce unused JavaScript warning in Google PageSpeed Insights tool.

1. What is Delay Js?

The Delay JavaScript feature helps improving the Reduce unused JavaScript warning in Google PageSpeed Insights tool. The Delay JavaScript feature does not promise to completely resolve the “Reduce unused JavaScript” warning. It only partially resolves the warning.

Loading some js files as soon as the page is opened slows the site down a lot, so loading some js resources as delay will contribute to the page loading faster.

We should immediately point out that unfortunately there is no plugin available which can solve the Reduce unused JavaScript warning in Google PageSpeed Insights tool completely.

2. How Does It Work?

Anyone familiar with the Lazy Load method can easily guess how the Delay JavaScript feature works because the working principles are very similar to each other.

Some Js resources are not loaded when the page is opened. User interaction such as moving the mouse, touching the screen or scrolling is needed to load the js sources.

3. Which Js Files Are Included?

Some users want all js files to be included. However, this can be a very dangerous action because it might cause too many errors, so we include js files which don’t cause problems when loaded as delay.

We try to include as many js resources as we can, so we need your help. You can contact us for the js resources you want us to include.

4. How to Enable it?

This is a beta feature so you need to follow the steps below to see the Delay JavaScript option on the settings of WP Fastest Cache.

You need to add the following lines after <?php which exists at the top of wp-config.php file.