canvas clearrect not working

Try this!

 

function canvasCleaner(){
    var canvas = document.getElementById('myCanvas');
    var ctx = canvas.getContext('2d', { alpha: false });
    var img = document.getElementById("img");
 
    //Canvas Clear
    //ctx.clearRect(0, 0, 3000, 3000); //not working :(
    ctx.canvas.width = ctx.canvas.width; //**canvas clear :)
    ctx.beginPath(); //canvas line clear
}