Autoptimize is a WordPress plugin that optimises website performance by aggregating, minifying, and compressing HTML, CSS, and JavaScript files.
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
jQuery plugin for seeing if the images are loaded.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.
WordPress Super Cache is a static caching plugin for WordPress.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.
WPMU DEV Smush is a WordPress plugin that allows you to optimise images without losing quality.