[JS - Get load time] Get server performance load time using javascript

JS - Get load time.js

function getLoadTime() {
    var now = new Date().getTime();
    
    // Get the performance object
    window.performance = window.performance || window.mozPerformance || window.msPerformance || window.webkitPerformance || {};
    var timing = performance.timing || {};
    if (timing) {
        var load_time = now - timing.navigationStart;   
        console.log('Load time: ' + load_time + 'ms');
    }
}

window.onload = function() {
    getLoadTime();
}