Support 103 Early Hints informational responses during top-level frame navigation. When a 103 response includes link headers Chromium tries to preload specified resources (including modulepreload) or preconnect to specified origins before the final response is received. This gives Web developers a way to optimize Core Web Vitals such as Largest Contentful Paint (LCP).


A few months ago, we announced a collaborative experiment [1] to measure the potential impact of 103 early hints. The results indicate that Early Hints could result in speed improvements on the order of a few hundred milliseconds (the sample size is a bit small though). Given these encouraging results, we are now moving forward with the next steps, starting with this intent to prototype. [1]




Specification link

Unknown standards status - check spec link for status

Status in Chromium


Origin trial (tracking bug)

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.



Last updated on 2022-05-15