How to save a html5 Canvas.toDataURl string as a png on a php backend -

after converting canvas image source using

 canvas.todataurl("image/png"); 

and passing php file, how save .png image on server?

it's simple, if have allow-url-fopen enabled. php supports data: url scheme then, , automatically decodes base64 , urlencoding.

preg_match('#^data:[\w/]+(;[\w=]+)*,[\w+/=%]+$#', $data=$_post["datau"]) , copy($data, "output.png"); 

but extract part after , , manually base64_decode() it.