Intervention: Blocking the load of cross-origin, parser-blocking scripts inserted via document.write for users on 2G

For users on slow connections such as 2G, the performance penalty from third-party scripts loaded via document.write is often so severe as to delay display of main page content for tens of seconds. This feature will block the load of cross-origin, parser-blocking scripts inserted via document.write in case of an HTTP cache miss for users on a 2G connection. The feature will only be applicable to such scripts in the main frame.

Comments

Launch slated for M55.

Documentation

Status in Chromium

Enabled by default (launch bug) in:

  • Chrome for desktop release 55
  • Chrome for Android release 55
  • Chrome for iOS release 55
  • Android WebView release 55
  • Opera release 55
  • Opera for Android release 55

Consensus & Standardization

  • No public signals
  • No public signals
  • No public signals
  • Positive

Owners

Last updated on 2017-01-12