bypr.nils

Smart Image Loader loads images which are visible in the initial viewport of your website before any images whose position is “below the fold”, outside the current viewport. Those images can be loaded as soon as the visible images are finished loading or “lazy loaded” when they would become visible. This can be useful for bandwidth saving on mobile devices.
There is no need to insert any additional code into your website, just install the plug-in.
The default settings are fine in most cases, but you may want to adjust them for optimization.
Smart Image Loader is tested and works down to Internet Explorer 7, disabled below.
Note: there is currently no support for (CSS) background images.

Smart Image Loader

Smart Image Loader is a fire-and-forget priority and lazy loader for image sources. Can be a huge performance boost especially for one pagers.

Adnan

WPBrigade

Inline CSS block helps in adding above the fold CSS or for your Advanced customization needs.

Inline CSS Block for Gutenberg

Inline CSS block helps in adding above the fold CSS or for your Advanced customization needs.

Smart Image Loader vs Inline CSS Block for Gutenberg