<!DOCTYPE html> <title> Transform animation winning over another transform animation in delay phase on the main-thread creates a stacking context </title> <style> span { height: 100px; width: 100px; position: fixed; background: green; top: 50px; } @keyframes TransformNone { from, to { transform: none; } } @keyframes Transform100px { from, to { transform: translateX(100px); } } // For preventing running on the compositor. @keyframes Width { from, to { width: 100px; } } #test { width: 100px; height: 100px; background: blue; animation: Transform100px 100s 100s, TransformNone 100s, Width 100s; } </style> <span></span> <div id="test"></div>