The onloadstart property of the GlobalEventHandlers mixin is an EventHandler representing the code to be called when the loadstart event is raised (when progress has begun on the loading of a resource.)
Syntax
img.onloadstart = funcRef;
Value
funcRef is the handler function to be called when the resource's loadstart event fires.
Examples
HTML content
<img src="myImage.jpg">
JavaScript content
// 'loadstart' fires first, then 'load', then 'loadend'
image.addEventListener('load', function(e) {
  console.log('Image loaded');
});
image.addEventListener('loadstart', function(e) {
  console.log('Image load started');
});
image.addEventListener('loadend', function(e) {
  console.log('Image load finished');
});
Specifications
| Specification | Status | Comment | 
|---|---|---|
| WHATWG HTML Living Standard The definition of 'onloadstart' in that specification. | Living Standard | Initial definition | 
Browser Compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) | 
|---|---|---|---|---|---|---|
| Basic support | (Yes) | 20 (12.10240) | (Yes) 52 (52)[1] | (Yes) | (Yes) | ? | 
| Feature | Android | Android Webview | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android | 
|---|---|---|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | 20 (12.10240) | (Yes) 52.0 (52)[1] | (Yes) | (Yes) | ? | (Yes) | 
[1] As of Firefox 52, The loadstart event is now fired on <img> elements.
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                       Contributors to this page: 
        Sebastianz, 
        chrisdavidmills
                    
                    
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