The following table shows levels of CSS support in modern browsers. Declarations are broken down by module, and level of support is tested on the latest versions of browsers - Firefox 2, Safari 2, Opera 9.2, Konqueror 3.5.7, IE7 - unless otherwise stated. Click on the declaration title to test it for yourself.

CSS 3 Support in key browsers
Firefox Safari Opera Konq. IE


Y Implemented in most recent version of browser.

* Implemented with browser-specific prefix (-moz-, -webkit-, etc).

~ Partially implemented.

n Implementation expected from this version of the browser (Firefox 3, Safari 3, etc).


[1] 'border-colors' doesn't currently exist in the CSS 3 specification.

[2] 'text-overflow' has not yet been clarified in the CSS 3 specification.

[3] The CSS 3 specification uses the property 'resizer'.

[4] 'border-radius' in Firefox contradicts the CSS 3 specification.

Backgrounds and Borders
background-clip Y* Y* Y~
background-origin Y* Y* Y~
background-size Y* Y*
multiple background-images Y* Y*
border-colors [1] Y*
border-image Y*
border-radius Y* [4] 3*
box-shadow 3*
HSL values Y Y Y
HSLA values 3 3
Opacity Y Y Y
RGBA values 3 3
text-overflow [2] Y Y Y
text-shadow 3 9.5 Y
Box Model
box-sizing Y* 3 Y Y
User Interface
resize [3] 3
Media Queries
media queries 3 Y
Multi-Column Layout
multi-column layout Y* 3*
speech Y*