jquery.js 1.11.3 and jquery-migrate.min.js 1.2.1 interfering with mobile device

After further testing based on a fresh WordPress 4.3.1 install, I realize the problem is not with JetPack but probably with WordPress core files.

These tests were made with the Twenty-Fifteen and Mobile-First themes. The WP install was plain default English with no translation files.

In both tests, Google’s Page Speed Insight reports for Mobile devices led to the same two jquery-related messages I reported in my preceding post.

Does anyone know why there are Mobile Device issues reported by Google when using up-to-date mobile ready versions of WordPress and themes?

Does anyone know why there are Mobile Device issues reported by Google when using up-to-date mobile ready versions of WordPress and themes?

It’s actually really hard to clear all warnings from Google’s Page Speed insights. Even Google’s own sites don’t always get a 100% rating (you can check Google News for example).

I think Pagespeed Insights is a good tool to notice the big issues, and improve your site’s performance, but I try to remember that I can’t fix everything; at one point, you’ll need to decide whether a certain feature on your site is worth the performance hit, and consequently the warning in Pagespeed Insights.

In Twenty Fifteen’s case, these 2 files are added to manage a few features, like keyboard navigation for images, as well as the navigation menu on mobile.

You could remove these 2 files by creating a Child Theme and dequeuing jQuery.

However, it’s possible that other features on your site require these 2 files. Jetpack’s Sharing buttons use jQuery, for example. At the end of the day, there are so many things relying on jQuery on modern sites that it might not be worth spending some time trying to remove those 2 files from your site.

I hope this clarifies things a bit.

Thank you Jeremy !

Google’s Page Speed insights helped me identifying issues that needed to be corrected, and contributed to fix some of the major issues.

You helped me realize that aiming for a perfect score could become a problem in itself.