This version: https://www.w3.org/TR/2018/WD-css-transitions-1-20181011/ Latest published version: https://www.w3.org/TR/css-transitions-1/ Editor's Draft: https://drafts.csswg.org/css-transitions/ Previous Versions: https://www.w3.org/TR/2017/WD-css-transitions-1-20171130/ https://www.w3.org/TR/2013/WD-css3-transitions-20131119/ Test Suite: http://test.csswg.org/suites/css-transitions-1_dev/nightl