Spec-compliant shadow blur-radius

Historically, Blink's blur-radius interpretation has been at odds with both the CSS and Canvas2D specs: Blink shadows cover about half the expected area (see linked bug). With this change Gaussian blur sigma is now computed as 1/2 blur-radius, as mandated by spec. Blink's shadow implementation now matches FireFox and Safari.


The main purpose of this CPS entry is to trickle out into release notes, in order to minimize the surprise factor associated with a user-visible change in blur-radius interpretation.



Working draft or equivalent

Status in Chromium


Enabled by default (tracking bug) in:

  • Chrome for desktop release 73
  • Chrome for Android release 73
  • Android WebView release 73

Consensus & Standardization

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

  • Shipped
  • No public signals
  • Shipped
  • Positive


Last updated on 2019-01-22