CSS 2.1 is Finally Final

It's only been 13 years, but CSS version 2.1 is now officially a W3C Recommendation — essentially meaning the specification is final. Which of course means you are now all free to use it in your web pages.

CSS2 became a W3C Recommendation on May 12, 1998, over 13 years ago. Since then the CSS Working Group has been developing CSS Level 2 Revision 1 (CSS 2.1) to correct errors and omissions from the original CSS2 specification. For context, the HTML 4 specification was approved on April 24, 1998. The HTML 4.01 specification was approved on December 24, 1999. Between those two versions, little more than a year and a half passed.

The W3C has a slightly confusing progression of a specification before it is considered a "standard." There are essentially four steps:

1. Working Draft (WD): This is the first time a proposed specification is shown to the public and open for comment.


2. Candidate Recommendation (CR): Significant features are mostly locked and feedback is requested in how to implement the standard.


3. Proposed Recommendation (PR): The specification has been submitted to the W3C Advisory Council for approval. Changes at this point are rare.


4. W3C Recommendation (REC): The specification is final and endorsed by the W3C. This is what the general public considers a final standard.

In July of last year I wrote up a post about the CSS 2.1 specification status (
CSS 2.1 Still Not Final). Bruce Lawson picked up on the irony in my post (or at least my bewildered expression) and used humor to convey just how this hasn't stopped anyone from implementing it for the last decade-plus (CSS 2.1 “not ready for use” says journalist).

The key reason that this is newsworthy is because CSS level 3 (CSS3) is relying on CSS 2.1 to be wrapped up before it can move forward to the final steps. The CSS Working Group acknowledges that future CSS specifications rely on this final step (read the original release from June 30, 2010: An Update on CSS 2.1):

[CSS] 2.1 must be released as a Web Standard because that's one of the current cornerstones of the architecture of the World Wide Web. We cannot make the next steps, CSS 3 even module by module, happen without 2.1 before.

In case you want to replace the last version of the CSS 2.1 specification that you have hanging on your refrigerator, you can grab the latest (today's) version at the W3C site:

• Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification: W3C Recommendation 07 June 2011

Just to make sure CSS3 isn't lost in the certain global buzz over CSS 2.1, the W3C pushed two more CSS specifications to W3C Recommendation status today:

• CSS Color Module Level 3: W3C Recommendation 07 June 2011


• A MathML for CSS Profile: W3C Recommendation 07 June 2011

For further reading, visit the press at the W3C site:

• Cascading Style Sheets Standard Boasts Unprecedented Interoperability (full release)


• Cascading Style Sheets Standard Boasts Unprecedented Interoperability (mini release)

Update: June 10, 2011

Net Magazine has a brief piece on the wrap-up of CSS 2.1 by interviewing some known standardistas and getting their thoughts on the milestone approach versus the constant iteration approach: It's official: W3C finalises CSS 2.1