Hello everyone.
I was asked to report my website for how I managed to pull off a 100/100 for google site speed. I guess I was already doing what Philippe has going on with using the combination of WP Fastest Cache and AutoOptimize. With all of the settings default or using the thread dealing with generatepress optimization page https://generatepress.com/fastest-wordpress-theme/ i could only get a 95/100 with google PageRank saying to eliminate CSS blocking.
Now users of WordPress will warn you not to use multiple cache plugins. Unforseen consequences and all. But I think what it comes right down to for me was telling which cache software what exactly to do. I told WP Fastest Cache to totally back away from all CSS optimization on my site. Then going back to AutoOptimize I checked one additional box to Also aggregate inline CSS? which got me to the magical 100 because the CSS is gone! It’s now apart of the HTML which in Googles mind is perfectly fine. Checking this option could result in other plugins failing to format due to use of dynamic CSS so use caution on this one!
Now there is some things I did a little differently from the GeneratePress Optimization page. Like I did not use the Async Javascript plugin. WP Fastest Cache was doing a bang up job already. Fastest Cache also took care of minification of html and JS.
Image optimization – if google speed test hits you with this and you got a linux box you could hammer through the folders of your entire WP site with utilities like ‘optipng’
find /path/to/wordpress/files/ -type f -name "*.png" -exec optipng -o2 -strip all {} \;
Stripping the meta from jpg files is good because Google does not like meta inside of images. It could confuse the search engine. jpegoptim is the linux utility to fix that!
find /path/to/wordpress/uploads/ -type f -name "*.jpg" -exec jpegoptim --strip-all {} \;
I also turn off all thumbnail images WordPress produces because WordPress’s libGDI hook is a functional tool for generating new images. But it sometimes blows PNG files out of proportion by converting them from 4-8bit to 24bit.
And don’t forget about WebP. The EWWW image optimizer plugin gives the ability to add a hook for the new format. Google loves sites that use their tech. But understand if you re-render all of your images through EWWW it will generate a bunch of WebP images filling up disk space on your site.
If you are getting render-blocking JS issues – This could be a result of too many fancy plugins. If you’re site has sections where a plugin is only used on a page or one entry. try and see if you can get an option to disable java-script of that plugin on all pages except for the one you want. It’s why I had to upgrade to FooBox Premium plugin for image viewing. So it only loaded when there was a gallery, instead of on every page of my site.
There’s a bunch of other stuff I did but it falls out of the scope of Google Speed Test. Anyhow, that’s my experience with it all. Hope it helps.