How we built it

Resource Hints - preconnect

Adds support for <link rel="preconnect" href="..."> (and the equivalent HTTP link header) as a hint that the browser should predictively open a connection to the supplied server/protocol for resources that will be needed later in the loading process.

Comments

There is some leeway on the actual preconnect and it is treated as a hint. In particular, the number of connections is left to the browser to decide. In cases where Chrome already has predictor information we may choose to ignore the preconnect hint entirely and use the historical knowledge we have from the predictor.

Documentation

Specification

Editor's draft

Status in Chromium

Enabled by default (launch bug) in:

  • Chrome for desktop release 46
  • Chrome for Android release 46
  • Chrome for iOS release 46
  • Android WebView release 46
  • Opera release 33
  • Opera for Android release 33

Consensus & Standardization

Owner

Last updated on 2015-10-16