Essential WordPress plugins for building fast loading optimized websites.
Plugins that help score high with GT-Metrix
Autoptimize
Autoptimize makes optimizing your site really easy. It can aggregate, minify and cache scripts and styles, injects CSS in the page head by default (but can also defer), moves and defers scripts to the footer and minifies HTML. The “Extra” options allow you to optimize Google Fonts and images, async non-aggregated JavaScript, remove WordPress core emoji cruft and more. As such it can improve your site’s performance even when already on HTTP/2! There is extensive API available to enable you to tailor Autoptimize to each and every site’s specific needs.
Every site is different and Autoptimize does take a little tinkering to get the settings right. My suggestion is to make 1 change then check for js errors.
WP-Optimize
Async JavaScript
BJ Lazy Load
Lazy loading makes your site load faster and saves bandwidth.
This plugin replaces all your post images, post thumbnails, gravatar images and content iframes with a placeholder and loads the content as it gets close to enter the browser window when the visitor scrolls the page. Lazy loading and easily be added with just a few lines of code as well see this post lazy load Script see post
Query Monitor
GT Metrix Image Optimization Losslessly compressing
*Please note that if you use both BJ Lazy and Optimole, you need to disable Javascript replacement & Lazy load from the Optimole admin.
Development
ACF PRO
Formidable Pro
Admin Column Pro
Shopping carts
Ecwid