Early Hints (HTTP 103)
Early Hints (HTTP 103 response status) is a mechanism that allows the server to send resource hints to the browser before the final HTML response is ready. For example, the server can send Early Hints to preload critical CSS, fonts, or images while it's still generating the HTML. This is particularly useful for optimizing sites that generate HTML dynamically and can provide significant performance improvements by allowing the browser to start preloading resources earlier.
Related web performance terms
- ETag
An ETag (entity tag) is an HTTP header that serves as a unique identifier for a specific version of a resource. It is a crucial mechanism for efficient cache validation.
- EXIF (Exchangeable Image File Format)
EXIF is metadata embedded within image files (like JPEGs) that contains information such as the camera settings, date, time, and sometimes GPS location where the photo was taken.
- Edge Cache (Fastly)
The Edge Cache is Fastly's distributed edge caching infrastructure that serves cached content from Fastly's Points of Presence (PoPs) around the world.
- Element Timing
Element Timing is a browser API that allows you to measure when specific elements on a page are rendered. This is particularly useful for creating custom performance metrics when Google's standard…