<!DOCTYPE html> <meta charset="utf-8"> <title>Bug 1219985: Basic rendering into a non-alpha canvas</title> <div style="width: 200px; height: 200px; background-color: red;"> <canvas id="c" width="200" height="200"></canvas> </div> <script> var c = document.getElementById('c'); var ctx = c.getContext('2d', { alpha: false }); ctx.fillStyle = 'green'; ctx.fillRect(50, 50, 100, 100); </script>