Clear canvas by setting width and height value
<!DOCTYPE html> <html> <head> <title>Learning the basics of canvas</title> <meta charset="utf-8"> //from w w w .ja v a2 s . c o m <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script> <script type="text/javascript"> $(document).ready(function() { let canvas = $("#myCanvas"); let context = canvas.get(0).getContext("2d"); context.fillStyle = "rgb(255, 0, 0)"; context.fillRect(40, 40, 100, 100); context.beginPath(); context.arc(230, 90, 50, 0, Math.PI*2, false); context.closePath(); context.fill(); // context.clearRect(230, 90, 50, 50); canvas.attr("width", canvas.width()); canvas.attr("height", canvas.height()); context.fillRect(4, 4, 100, 100); }); </script> </head> <body> <canvas id="myCanvas" width="500" height="500"> <!-- Insert fallback content here --> </canvas> </body> </html>