In this deep dive session on web performance, attendees will learn about the intricate process browsers go through when loading a webpage and its subresources. The talk covers various factors that browsers consider, such as render/parsing blocking resources, preload scanner, resource hints, loading modifiers, fetchpriority, responsive images, and more. Interestingly, browsers have different methods for deciding when to load resources, with some intentionally delaying requests. The session aims to provide insights on influencing browser behavior and optimizing resource loading. Attendees will gain a better understanding of browser quirks and how to tackle common issues, ensuring important assets are prioritized correctly for optimal performance.
https://fosdem.org/2025/schedule/event/fosdem-2025-4852-how-browsers-really-load-web-pages/