Web Performance

2 articles

Software Engineering 16 Sep 2026 6 min read

HTTP 103 Early Hints Separate Speculation From Final Response Semantics

An HTTP server can emit a 103 Early Hints informational response before it has produced the final response. A client may act on suitable fields in that interim message, such as starting a preload named by Link, even though the eventual status code, header fields, and representation are still pending. This creates a deliberate split between speculative work and authoritative response semantics. The interim response can move selected preparation earlier in time, but it cannot stand in for the final response or determine its meaning.

Software Engineering HTTP

Web Development 01 Sep 2026 3 min read

Use HTTP 103 Early Hints Without Breaking Page Delivery

A server may need time to produce an HTML response even though it already knows that the page will require a stylesheet or other critical resource. HTTP 103 Early Hints lets the server send selected Link hints before the final response so a supporting client can begin useful work sooner. The optimization is optional: the final response still determines the page result. Understand the response sequence A simplified exchange looks like this:

Web Development HTTP