This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The loadEventStart read-only property returns a timestamp representing the time value equal to the time immediately before the load event of the current document is fired.
perfEntry.loadEventStart;
A timestamp representing a time value equal to the time immediately before the load event of the current document is fired.
The following example illustrates this property's usage.
function print_nav_timing_data() {
// Use getEntriesByType() to just get the "navigation" events
var perfEntries = performance.getEntriesByType("navigation");
for (var i=0; i < perfEntries.length; i++) {
console.log("= Navigation entry[" + i + "]");
var p = perfEntries[i];
// dom Properties
console.log("DOM content loaded = " + (p.domContentLoadedEventEnd - p.domContentLoadedEventStart));
console.log("DOM complete = " + p.domComplete);
console.log("DOM interactive = " + p.interactive);
// document load and unload time
console.log("document load = " + (p.loadEventEnd - p.loadEventStart));
console.log("document unload = " + (p.unloadEventEnd - p.unloadEventStart));
// other properties
console.log("type = " + p.type);
console.log("redirectCount = " + p.redirectCount);
}
}
| Specification | Status | Comment |
|---|---|---|
| Navigation Timing Level 2 The definition of 'loadEventStart' in that specification. | Editor's Draft | Initial definition. |
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|
| Basic support. | 57 | 58 (58) | No support | 44 | No support |
| Feature | Android Webview | Chrome for Android | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support. | 57 | 57 | 58.0 (58) | No support | 44 | No support |
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https://developer.mozilla.org/en-US/docs/Web/API/PerformanceNavigationTiming/loadEventStart