Render-blocking JS is the most annoying and unresolvable error message

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Reading Time: 2 minutesCreative Speed Strategy using free plugins and free themes.

Save the Internet from WordPress speed abuse.

We don’t recommend using Google’s PageSpeed Insight tools for doing mobile website benchmarking – or even for desktop. We avoid this tool. We refer you to the following articles as to why:


Why the .@Google Mobile Test Tool Is Absolute Crap >
Why you Shouldn’t Care About Google PageSpeed Insights >
Why Trying to Get 95+ on Google PageSpeed Insights for Your WordPress Site Will Drive You Mad! >
The Truth about Google Pagespeed Insights >

Better tools for evaluation are pingdom.com and WebPagetest.org.
Note: WebPagetest is an open-source project owned by Google.

Deferring Javascript breaks WordPress.

Google’s Bogus Error Message for Mobile Anxiety

Should Fix:
Eliminate render-blocking JavaScript and CSS in above-the-fold content.

R
ender-blocking JS is the most annoying and unresolvable error message Google’s mobile test delivers. It pushes some perfectionists to the brink of frothing madness. We’ve decided it must be ignored completely if you use WordPress. Give yourself a break. It’s not you that’s bad. It’s Google.

When you’re using WordPress for website production, it’s an impossible situation. The most basic components of WordPress trigger the “render-blocking JS” error message. No other method of speed testing uses render-blocking JS as a parameter. It’s not worth reporting.

Many supposed solutions are created by plugin authors attempting to resolve this frustrating error message. We tested all of the 8 plugins below. They do not work as claimed. They are not “plug-and-play.” They don’t eliminate the “render-blocking” error message on PageSpeed Insights. Nor do they improve page load time in the least. Three plugins broke the page being tested. Those three are marked with a red asterisk.

These are not simple or easy plugins. In most cases, they are dangerous in the wrong, inexperienced hands. You can easily damage your site. We recommend you not use them. They are esoteric fluff. Their claims are presented below but don’t believe them without testing for confirmation on your site. We had no success. This is a warning.

above the fold optimization 103.4k
Enables to pass the “Eliminate render-blocking JavaScript and CSS in above-the-fold content”-rule from Google PageSpeed Insights

performance optimization order styles and javascript 5k
Ordering StyleSheet and JavaScript (external and inline) for performance optimization. The plugin will also collect different inline scripts to one place.

wp deferred javascripts 14k
Defer the loading of all JavaScripts added by the way of wp_enqueue_script(), using LABJS. The result is a significant optimization of loading time. It is compatible with all WordPress JavaScript functions (wp_localize_script(), js in header, in footer…) and works with all well coded plugins. If a plugin or a theme is not properly enqueuing scripts, your site may not work.

external files optimizer* 4.7k
Automatically combine and compress css/js files generate with wp_head() and wp_footer()

head cleaner* 262k
Cleaning tags from your WordPress header and footer. To speed up the loading of JavaScript and CSS. PHP5 required.

headjs loader* 15k
Load your Javascript files via Head JS. Caution: this plugin can cause major issues with the javascript on your site if not implemented properly. Please be sure to test on a development server first.

wp asset clean up 34k
Make your website load FASTER by preventing specific scripts (.JS) & styles (.CSS) from loading on pages/posts and home page. WP Asset Clean Up scans your page and detects all the assets that are loaded. When editing a page/post select the ones you DO NOT wish to load.

wp super simple speed 7k
Super Simple Speed is a stable and powerful plugin that dramatically increases your WordPress page load speed and gives you a better performance score on the major speed testing services. Unlike most other similar plugins, WP Super Simple Speed is lightweight (less than 20kb in size), and has no clutter or unnecessary code or configs. Simple performance optimization without any hassle.

PagePipe helps you balance performance and mobile branding.

Steve Teare
performance engineer

Creative Speed Strategy using free plugins and free themes.

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by - Stacy M. Jones