title: canvas.toDataURL() download size limit
body: <p>I am attempting to download an entire canvas image using canvas.toDataURL().  The image is a map rendered on the canvas (Open Layers 3).</p>
  
  <p>In Firefox I can use the following to download the map on the click of a link:</p>
  
  <pre><code>var exportPNGElement = document.getElementById('export_image_button');
  
  if ('download' in exportPNGElement) {
      map.once('postcompose', function(event) {
      var canvas = event.context.canvas;
      exportPNGElement.href = canvas.toDataURL('image/png');
  });
  
  map.renderSync();
  
  } else {
  alert("Sorry, something went wrong during our attempt to create the image");
  }
  </code></pre>
  
  <p>However in Chrome and Opera I'm hitting a size limit on the link.  I have to physically make the window smaller for the download to work.</p>
  
  <p>There are size limit differences between browsers, Chrome is particularly limiting.  A similar post here (<strong>over 2 years old now</strong>) suggests an extensive server side workaround:</p>
  
  <p><a href="https://stackoverflow.com/questions/16156402/canvas-todataurl-for-large-canvas">canvas.toDataURL() for large canvas</a></p>
  
  <p>Is there a client side work around for this at all?  </p>