Percentage opacity

Adds support for percentage values to the opacity properties, specifically, opacity, stop-opacity, fill-opacity, stroke-opacity, and shape-image-threshold. For example, opacity: 50%; is equivalent to opacity: 0.5; https://drafts.csswg.org/css-color/#transparency

This brings consistency and spec compliance. The rgba() function already accepts percentage alpha value, for example rgba(0, 255, 0, 50%).

Documentation

• https://www.w3.org/TR/css-color-4/#transparency
• https://www.w3.org/TR/css-color-4/#typedef-alpha-value

Specification

Working draft or equivalent

Status in Chromium

Blink components: Blink>CSS

Enabled by default (tracking bug) in:

• Chrome for desktop release 78
• Chrome for Android release 78

Consensus & Standardization

• Firefox: Shipped
• Edge: No public signals
• Safari: Public support
• Web Developers: No signals

Owners

• hanlee.dev@gmail.com
• ericwilligers@chromium.org

Last updated on 2019-08-07