The HTMLCanvasElement.toDataURL() method returns a data URI containing a representation of the image in the format specified by the type parameter (defaults to PNG). The returned image is in a resolution of 96 dpi.

  • If the height or width of the canvas is 0 or larger than the maximum canvas size, the string "data:," is returned.
  • If the requested type is not image/png, but the returned value starts with data:image/png, then the requested type is not supported.
  • Chrome also supports the image/webp type.


canvas.toDataURL(type, encoderOptions);


type Optional
A DOMString indicating the image format. The default format type is image/png.
encoderOptions Optional
A Number between 0 and 1 indicating the image quality to use for image formats that use lossy compression such as image/jpeg and image/webp.
If this argument is anything else, the default value for image quality is used. The default value is 0.92. Other arguments are ignored.

Return value

A DOMString containing the requested data URI.


The canvas's bitmap is not origin clean; at least some of its contents have or may have been loaded from a site other than the one from which the document itself was loaded.


Given this <canvas> element:

<canvas id="canvas" width="5" height="5"></canvas>

You can get a data-URL of the canvas with the following lines:

var canvas = document.getElementById('canvas');
var dataURL = canvas.toDataURL();
// "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNby

Setting image quality with jpegs

var fullQuality = canvas.toDataURL('image/jpeg', 1.0);
// data:image/jpeg;base64,/9j/4AAQSkZJRgABAQ...9oADAMBAAIRAxEAPwD/AD/6AP/Z"
var mediumQuality = canvas.toDataURL('image/jpeg', 0.5);
var lowQuality = canvas.toDataURL('image/jpeg', 0.1);

Example: Dynamically change images

You can use this technique in coordination with mouse events in order to dynamically change images (gray-scale vs. color in this example):


<img class="grayscale" src="myPicture.png" alt="Description of my picture" />


window.addEventListener('load', removeColors);

function showColorImg() { = 'none'; = 'inline';

function showGrayImg() { = 'inline'; = 'none';

function removeColors() {
  var aImages = document.getElementsByClassName('grayscale'),
      nImgsLen = aImages.length,
      oCanvas = document.createElement('canvas'),
      oCtx = oCanvas.getContext('2d');
  for (var nWidth, nHeight, oImgData, oGrayImg, nPixel, aPix, nPixLen, nImgId = 0; nImgId < nImgsLen; nImgId++) {
    oColorImg = aImages[nImgId];
    nWidth = oColorImg.offsetWidth;
    nHeight = oColorImg.offsetHeight;
    oCanvas.width = nWidth;
    oCanvas.height = nHeight;
    oCtx.drawImage(oColorImg, 0, 0);
    oImgData = oCtx.getImageData(0, 0, nWidth, nHeight);
    aPix =;
    nPixLen = aPix.length;
    for (nPixel = 0; nPixel < nPixLen; nPixel += 4) {
      aPix[nPixel + 2] = aPix[nPixel + 1] = aPix[nPixel] = (aPix[nPixel] + aPix[nPixel + 1] + aPix[nPixel + 2]) / 3;
    oCtx.putImageData(oImgData, 0, 0);
    oGrayImg = new Image();
    oGrayImg.src = oCanvas.toDataURL();
    oGrayImg.onmouseover = showColorImg;
    oColorImg.onmouseout = showGrayImg;
    oCtx.clearRect(0, 0, nWidth, nHeight); = "none";
    oColorImg.parentNode.insertBefore(oGrayImg, oColorImg);


Specification Status Comment
HTML Living Standard
The definition of 'HTMLCanvasElement.toDataURL' in that specification.
Living Standard No change since the latest snapshot, HTML5
HTML 5.1
The definition of 'HTMLCanvasElement.toDataURL' in that specification.
The definition of 'HTMLCanvasElement.toDataURL' in that specification.
Recommendation Snapshot of the HTML Living Standard containing the initial definition.

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
toDataURLChrome Full support 1Edge Full support 12Firefox Full support 2IE Full support 9Opera Full support 9Safari Full support 4WebView Android Full support 1Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support 10.1Safari iOS Full support 3.2Samsung Internet Android Full support 1.0


Full support
Full support

See also