<!DOCTYPE HTML> <body> <canvas id="canv" width="5" height="5"></canvas> <script> var canv = document.getElementById("canv"); var ctx = canv.getContext("2d"); ctx.fillStyle = "red"; // 0 size font shouldn't assert! ctx.font = "0px Arial"; ctx.shadowColor = '#f00'; ctx.shadowBlur = 4; ctx.fillText("A", 0, 0); document.documentElement.className = ""; </script> </body> </html>