WP Simple Thimble

This plugin embeds or in-lines image/css/js content into the page before it’s loaded. This really improves page load speed scores, and can really improve actual load time if either the network connection is not blazingly fast, server side caching is used, or a combination of the two.

Warnings that are commonly eliminated in page load speed testing tools include

Optimize images Leverage browser caching Remove query strings from static resources Specify image dimensions Minify JavaScript Minify HTML Avoid bad requests Avoid a character set in the meta tag Avoid landing page redirects Defer parsing of JavaScript Inline small CSS Inline small JavaScript Minify CSS Minimize request size Optimize the order of styles and scripts Put CSS in the document head Serve resources from a consistent URL Serve scaled images Avoid CSS @import Combine images using CSS sprites Use a Content Delivery Network (CDN) Reduce the number of DOM elements Make fewer HTTP requests Minify JavaScript and CSS Put CSS at the top Put JavaScript at bottom Avoid AlphaImageLoader filter Avoid CSS expressions Reduce DNS lookups

The cases where some of these may still pop up would be a limitation of this project https://github.com/aadel112/simple-thimble, and you’ll note that these are all limitations that are actively being developed to be fixed.