The Resource Timing API received an update and will soon include a renderBlockingStatus field to find render-blocking resources.
Topic: Performance
Apple doesn't support AVIF in Safari because macOS/iOS don't support the image format and I understand their approach.
A
pictureelement snippet to load properly resized responsive webp images in browsers that support them.slowfil.es is a service to evaluate if slow JavaScript/CSS files affect page performance.
The new
content-visibilityCSS property explained by Surma and Jake.