>Firefox, conversely, doesn't have the canvas.toBlob() method, so if you want to convert a canvas to a Blob, you need to use canvas.toDataURL() and convert the dataURL to a Blob instead. blob-util does this under the hood.<p>I don't know where they are getting this. Firefox proposed[1] the toBlob() method, and implemented[2] it in Fx19.<p>[1] <a href="https://lists.w3.org/Archives/Public/public-whatwg-archive/2011Apr/0132.html" rel="nofollow">https://lists.w3.org/Archives/Public/public-whatwg-archive/2...</a><p>[2] <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=648610" rel="nofollow">https://bugzilla.mozilla.org/show_bug.cgi?id=648610</a>