The decoding property of the HTMLImageElement interface represents a hint given to the browser on how it should decode the image.


refStr = imgElem.decoding;
imgElem.decoding = refStr;


A DOMString representing the decoding hint. Possible values are:

  • sync: Decode the image synchronously for atomic presentation with other content.
  • async: Decode the image asynchronously to reduce delay in presenting other content.
  • auto: Default mode, which indicates no preference for the decoding mode. The browser decides what is best for the user.


var img = new Image();
img.decoding = 'sync';
img.src = 'img/logo.png'; 


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

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
decodingChrome Full support 65Edge ? Firefox Full support 63IE No support NoOpera Full support YesSafari Full support 11.1WebView Android Full support 65Chrome Android Full support 65Firefox Android Full support 63Opera Android ? Safari iOS Full support 11.3Samsung Internet Android ?


Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown

See also


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