JSFiddle - React, Tailwind, and code Playground

JavaScript

var canvas = document.createElement('canvas');
var ctx = canvas.getContext("2d");
var canvasBlocker=false;
try{
	ctx.getImageData(0,0,0,0);
}catch(err){
	try{
		console.log(err.name);
  }catch(err2){
  	canvasBlocker=true;
  }
}
if(canvasBlocker){
	alert("Canvas blocker detected.");
}else{
	alert("No canvas blocker detected");
}