Cloudflare Browser Insights is a tool that measures the performance of websites from the perspective of users.
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Next.js is a React framework for developing single page Javascript applications.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.