The CanvasRenderingContext2D.putImageData() method of the Canvas 2D API paints data from the given ImageData object onto the canvas. If a dirty rectangle is provided, only the pixels from that rectangle are painted. This method is not affected by the canvas transformation matrix.

Note: Image data can be retrieved from a canvas using the getImageData() method.

You can find more information about putImageData() and general manipulation of canvas contents in the article Pixel manipulation with canvas.


void ctx.putImageData(imageData, dx, dy);
void ctx.putImageData(imageData, dx, dy, dirtyX, dirtyY, dirtyWidth, dirtyHeight);


An ImageData object containing the array of pixel values.
Horizontal position (x coordinate) at which to place the image data in the destination canvas.
Vertical position (y coordinate) at which to place the image data in the destination canvas.
dirtyX Optional
Horizontal position (x coordinate) of the top-left corner from which the image data will be extracted. Defaults to 0.
dirtyY Optional
Vertical position (y coordinate) of the top-left corner from which the image data will be extracted. Defaults to 0.
dirtyWidth Optional
Width of the rectangle to be painted. Defaults to the width of the image data.
dirtyHeight Optional
Height of the rectangle to be painted. Defaults to the height of the image data.

Errors thrown

Thrown if any of the arguments is infinite.
Thrown if the ImageData object's data has been detached.


Understanding putImageData

To understand what this algorithm does under the hood, here is an implementation on top of CanvasRenderingContext2D.fillRect().


<canvas id="canvas"></canvas>


var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');

function putImageData(ctx, imageData, dx, dy,
    dirtyX, dirtyY, dirtyWidth, dirtyHeight) {
  var data =;
  var height = imageData.height;
  var width = imageData.width;
  dirtyX = dirtyX || 0;
  dirtyY = dirtyY || 0;
  dirtyWidth = dirtyWidth !== undefined? dirtyWidth: width;
  dirtyHeight = dirtyHeight !== undefined? dirtyHeight: height;
  var limitBottom = dirtyY + dirtyHeight;
  var limitRight = dirtyX + dirtyWidth;
  for (var y = dirtyY; y < limitBottom; y++) {
    for (var x = dirtyX; x < limitRight; x++) {
      var pos = y * width + x;
      ctx.fillStyle = 'rgba(' + data[pos*4+0]
                        + ',' + data[pos*4+1]
                        + ',' + data[pos*4+2]
                        + ',' + (data[pos*4+3]/255) + ')';
      ctx.fillRect(x + dx, y + dy, 1, 1);

// Draw content onto the canvas
ctx.fillRect(0, 0, 100, 100);
// Create an ImageData object from it
var imagedata = ctx.getImageData(0, 0, 100, 100);
// use the putImageData function that illustrates how putImageData works
putImageData(ctx, imagedata, 150, 0, 50, 50, 25, 25);


Data loss due to browser optimization

 Due to the lossy nature of converting to and from premultiplied alpha color values, pixels that have just been set using putImageData() might be returned to an equivalent getImageData() as different values.


const canvas = document.createElement("canvas");
canvas.width = 1;
canvas.height = 1;
const context = canvas.getContext("2d");
const imgData = context.getImageData(0, 0, canvas.width, canvas.height);
const pixels =;
pixels[0 + 0] = 1;
pixels[0 + 1] = 127;
pixels[0 + 2] = 255;
pixels[0 + 3] = 1;
console.log("before:", pixels);
context.putImageData(imgData, 0, 0);
const imgData2 = context.getImageData(0, 0, canvas.width, canvas.height);
const pixels2 =;
console.log("after:", pixels2);

The output might look like:

before: Uint8ClampedArray(4) [ 1, 127, 255, 1 ]
after: Uint8ClampedArray(4) [ 255, 255, 255, 1 ]


Specification Status Comment
HTML Living Standard
The definition of 'CanvasRenderingContext2D.putImageData' in that specification.
Living Standard  

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
putImageDataChrome Full support YesEdge Full support 12Firefox Full support 2IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes


Full support  
Full support

Gecko-specific notes

  • Starting in Gecko 10.0 (Firefox 10.0 / Thunderbird 10.0 / SeaMonkey 2.7), non-finite values to any of these parameters cause the call to putImageData() to be silently ignored, rather than throwing an exception.
  • To comply with the specification, starting with Gecko 16.0 (Firefox 16.0 / Thunderbird 16.0 / SeaMonkey 2.13), a call with an invalid number of arguments (only 3 or 7 arguments are valid), will now throw an error (bug 762657).

See also