Question

Div ‘canvasesdiv’ element contains three HTML5 canvases.

<div style="position: relative; width: 400px; height: 300px;" id="canvasesdiv">
    <canvas width="400" height="300px" style="z-index: 1; position: absolute; left: 0px; top: 0px;" id="layer1" />
    <canvas width="400" height="300px" style="z-index: 2; position: absolute; left: 0px; top: 0px;" id="layer2"/>
    <canvas width="400" height="300px" style="z-index: 3; position: absolute; left: 0px; top: 0px;" id="layer3"/>
</div>

How can I save an image combining all canvases present inside the div ‘canvasesdiv’ at client side using JavaScript?

Answer 1

This is very similar to a previous question that I answered:
save-many-canvas-element-as-image

In summary: draw all of the canvases to one of them and then get the image via toDataURL()