We're looking for a person or people to help audit MDN to find places we could speed up. Is this you or someone you know? Check out the RFP: https://mzl.la/2IHcMiE


The connectEnd read-only property returns the timestamp immediately after the browser finishes establishing the connection to the server to retrieve the resource. The timestamp value includes the time interval to establish the transport connection, as well as other time intervals such as SSL handshake and SOCKS authentication.

Note: This feature is available in Web Workers.



Return value

A DOMHighResTimeStamp representing the time after a connection is established.


In the following example, the value of the *Start and *End properties of all "resource" type events are logged.

function print_PerformanceEntries() {
  // Use getEntriesByType() to just get the "resource" events
  var p = performance.getEntriesByType("resource");
  for (var i=0; i < p.length; i++) {
function print_start_and_end_properties(perfEntry) {
  // Print timestamps of the *start and *end properties 
  properties = ["connectStart", "connectEnd",
                "domainLookupStart", "domainLookupEnd",
                "redirectStart", "redirectEnd",
                "responseStart", "responseEnd",

  for (var i=0; i < properties.length; i++) {
    // check each property
    var supported = properties[i] in perfEntry;
    if (supported) {
      var value = perfEntry[properties[i]];
      console.log("... " + properties[i] + " = " + value);
    } else {
      console.log("... " + properties[i] + " = NOT supported");


Specification Status Comment
Resource Timing Level 1
The definition of 'connectEnd' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support43 Yes401032 No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support4343 Yes4232 No ?

Document Tags and Contributors

 Contributors to this page: ExE_Boss, chrisdavidmills, abbycar, rolfedh, AFBarstow
 Last updated by: ExE_Boss,