TheredirectEnd read-only property returns atimestamp immediately after receiving the last byte of the response of the last redirect.

When fetching a resource, if there are multiple HTTP redirects, and any of the redirects have an origin that is different from the current document, and the timing allow check algorithm passes for each redirected resource, this property returns the time immediately after receiving the last byte of the response of the last redirect; otherwise, zero is returned.

To get the amount of redirects, see alsoPerformanceNavigationTiming.redirectCount.

Value

TheredirectEnd property can have the following values:

• Atimestamp immediately after receiving the last byte of the response of the last redirect.
• 0 if there is no redirect.
• 0 if the resource is a cross-origin request and noTiming-Allow-Origin HTTP response header is used.

Examples

Measuring redirection time

TheredirectEnd andredirectStart properties can be used to measure how long the redirection takes.

const redirect = entry.redirectEnd - entry.redirectStart;

Example using aPerformanceObserver, which notifies of newresource performance entries as they are recorded in the browser's performance timeline. Use thebuffered option to access entries from before the observer creation.

const observer = new PerformanceObserver((list) => {  list.getEntries().forEach((entry) => {    const redirect = entry.redirectEnd - entry.redirectStart;    if (redirect > 0) {      console.log(`${entry.name}: Redirect time: ${redirect}ms`);    }  });});observer.observe({ type: "resource", buffered: true });

Example usingPerformance.getEntriesByType(), which only showsresource performance entries present in the browser's performance timeline at the time you call this method:

const resources = performance.getEntriesByType("resource");resources.forEach((entry) => {  const redirect = entry.redirectEnd - entry.redirectStart;  if (redirect > 0) {    console.log(`${entry.name}: Redirect time: ${redirect}ms`);  }});

Cross-origin timing information

If the value of theredirectEnd property is0, the resource might be a cross-origin request. To allow seeing cross-origin timing information, theTiming-Allow-Origin HTTP response header needs to be set.

For example, to allowhttps://developer.mozilla.org to see timing resources, the cross-origin resource should send:

Timing-Allow-Origin: https://developer.mozilla.org

Specifications

Browser compatibility

See also

• PerformanceNavigationTiming.redirectCount
• Timing-Allow-Origin