In addition to removing unused CSS, there are many ways we can still improve the overall loading speed of a WordPress website.
Scripts
Serve Fonts Locally
When enabled Google fonts will be served locally. Can only be enabled after downloading the fonts on Fonts tab.
Preload Fonts
Preloading fonts can help improve loading speeds. When this option is enabled, the MinimalCSS generated file will be parsed for any WOFF2 fonts and a corresponding rel=”preload” element is added.
TIP: Depending on the number of fonts in use on your website, preloading the fonts might actually hurt performance. Test the Core Web Vitals scores with and without this option to see how your site performs.
Prefetch Google Tag Manager
To improve the loading of Google Tag Manager, this flag add a DNS Prefect for the GTM URL.
Delay Scripts
When enabled, the plugin will delay the loading of JavaScript scripts. The scripts you list will be delayed by up to 5 seconds or when user activity is detected – such as mouse scroll.
Popular scripts such as Google Analytics and Facebook Messenger and various chatbots are good examples of scripts you can add to the list.
Here’s a starter list you can try:
google.com
google-analytics.com
googletagmanager.com
hotjar.com
tawk.to
Media
Remove MediaElement
If you’re not using the built-in video or audio WordPress shortcodes to display HTML5 video or audio elements on your website, you can remove the WordPress Media Element and reduce the number of CSS and JavaScript files loaded on the site.
Optimize Video Delivery
When enabled, Youtube videos will be rendered using a light JavaScript library called Lite Youtube. This has a similar effect as lazy loading images. The Youtube files will not be loaded until a user clicks the play button.
Please note this impacts on Youtube videos that have been embedded directly on a webpage, and not videos that play in a popup overlay.
Lazy Load Background Images
By default, background images are not lazy loaded. This means browsers will have to download them as part of the initial page load. To help mitigate this issue, any background images tagged with CSS Class “mcss-lazy” will be hidden until those elements are in view.
Click here for more detailed information.
Preload Selected Page Images
On the Pages tab, you can select to have certain images be preloaded to improve performance. This Global flag needs to be enabled here for the preloading to work across the site. If you want to disable this feature for all pages, in case of any issues, you can disable this feature here.
Preload Featured Image
If this flag is enabled, featured images for Post types (blog posts, WooCommerce products, etc) will be automatically preloaded.
Background Image CSS Selector
Preload background images that use the specified CSS selector (e.g. page-title).
WordPress Defaults
Disable WordPress Emoji
Disable the loading the wp-emoji-release.min.js file.
Disable Embeds
Disable oEmbed discovery links in the header of the website.
Remove WordPress Shortlink
Remove the rel=shortlink meta tag from the header.
Remove RSD Link
Disable the RSD (Real Simple Discovery) tag from the header.
Disable Windows Writer Support
Removes the wlwmanifest link from the website header.
Disable REST API
Remove the Link header used by the Rest API.
Disable Gutenberg Scripts
Remove Gutenberg Blocks Scripts/Styles from the front-end.
Remove jQuery Migrate Script
Remove jQuery Migrate Script.