Bandwidth utility using javascript

Question

IS there any utility to measure bandwidth from my server to the client or any standard APIS.Need this for web application

Answer 1

    // Network connection - https://github.com/daniellmb/downlinkmax
var connectionSpeed = function() 
{
    // Deal with vendor prefixes
    var defaultSpeed = false,
        navigator = window.navigator,
        connection = navigator.connection || navigator.mozConnection || navigator.webkitConnection || null;
    if( ! connection )
        return defaultSpeed;

    // assume W3C Editor's Draft 09 October 2014
    if( 'downlinkMax' in connection )
    {
        var downlinkMax = connection.downlinkMax;
        if( ! downlinkMax )
            return defaultSpeed;
        if( ! isFinite(downlinkMax) )
            return defaultSpeed;
        return downlinkMax;
    }
    // assume W3C Working Draft 29 November 2012
    if( 'bandwidth' in connection )
    {
        var bandwidth = connection.bandwidth;
        if( ! bandwidth )
            return defaultSpeed;
        if( isNaN(speed) )
            return defaultSpeed;
        // standardize connection.bandwidth value by converting megabytes per second (MB/s) to megabits per second (Mbit/s)
        return bandwidth * 8;
    }
    // assume W3C Working Draft 07 June 2011
    switch( connection.type )
    {
        // convert connection.type value to approximate downlink values
        // speed estimate is based on the median downlink value for common devices in megabits per second (Mbit/s)
        case 'none':
            return 0;
        case '2g':
            return 0.134;
        case 'bluetooth':
        case 'cellular':
            return 2;
        case '3g':
            return 8.95;
        case '4g':
            return 100;
        case 'ethernet':
            return 550;
        case 'wifi':
            return 600;            
    }
    return defaultSpeed;
};