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The redirectStart property returns a timestamp representing the start time of the fetch which that initiates the redirect.

If there are HTTP redirects when fetching the resource and if any of the redirects are not from the same origin as the current document, but the timing allow check algorithm passes for each redirected resource, this property returns the starting time of the fetch that initiates the redirect; otherwise, zero is returned.

This property is Read only .



Return value

A timestamp representing the start time of the fetch which initiates the redirect.


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 PerformanceEntry *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
The definition of 'redirectStart' in that specification.
Editor's Draft Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support. 43 40 10 32 No support
Feature Android Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support. 4.4 42 ? 10.0 32 No support

Document Tags and Contributors

 Contributors to this page: rolfedh, AFBarstow
 Last updated by: rolfedh,