CSS Animations Module Level 1

Editor’s Draft,

More details about this document
This version:
https://drafts.csswg.org/css-animations/
Latest published version:
https://www.w3.org/TR/css-animations-1/
Previous Versions:
Feedback:
CSSWG Issues Repository
Inline In Spec
Editors:
(Apple Inc.)
L. David Baron (Google)
Tab Atkins Jr. (Google)
(Invited Expert)
Former Editors:
David Hyatt (Apple Inc.)
Chris Marrin (Apple Inc.)
(Adobe)
Suggest an Edit for this Spec:
GitHub Editor
Issues List:
https://github.com/w3c/csswg-drafts/labels/css-animations-1

Abstract

This CSS module describes a way for authors to animate the values of CSS properties over time, using keyframes. The behavior of these keyframe animations can be controlled by specifying their duration, number of repeats, and repeating behavior.

CSS is a language for describing the rendering of structured documents (such as HTML and XML) on screen, on paper, etc.

Status of this document

This is a public copy of the editors’ draft. It is provided for discussion only and may change at any moment. Its publication here does not imply endorsement of its contents by W3C. Don’t cite this document other than as work in progress.

Please send feedback by filing issues in GitHub (preferred), including the spec code “css-animations” in the title, like this: “[css-animations] …summary of comment…”. All issues and comments are archived. Alternately, feedback can be sent to the (archived) public mailing list www-style@w3.org.

This document is governed by the 18 August 2025 W3C Process Document.