Web/API/PerformanceServerTiming

Note: This feature is available in Web Workers.

Secure contextThis feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The PerformanceServerTiming interface surfaces server metrics that are sent with the response in the Server-Timing HTTP header.

This interface is restricted to the same origin, but you can use the Timing-Allow-Origin header to specify the domains that are allowed to access the server metrics. Note that this interface is only available in secure contexts (HTTPS) in some browsers.

Properties

PerformanceServerTiming.descriptionRead only: A DOMString value of the server-specified metric description, or an empty string.
PerformanceServerTiming.durationRead only: A double that contains the server-specified metric duration, or value 0.0.
PerformanceServerTiming.nameRead only: A DOMString value of the server-specified metric name.

Methods

PerformanceServerTiming.toJSON(): Returns a DOMString that is the JSON representation of the PerformanceServerTiming object.

Example

Given a server that sends the Server-Timing header, for example a node.js server like this:

const http = require('http');

function requestHandler(request, response) {
  const headers = {
    'Server-Timing': `
      cache;desc="Cache Read";dur=23.2,
      db;dur=53,
      app;dur=47.2
    `.replace(/\n/g, '')
  };
  response.writeHead(200, headers);
  response.write('');
  return setTimeout(_ => {
   response.end();
 }, 1000)
};

http.createServer(requestHandler).listen(3000).on('error', console.error);

The PerformanceServerTiming entries are now observable from JavaScript via the PerformanceResourceTiming.serverTiming property:

let entries = performance.getEntriesByType('resource');
console.log(entries[0].serverTiming);
// 0: PerformanceServerTiming {name: "cache", duration: 23.2, description: "Cache Read"}
// 1: PerformanceServerTiming {name: "db", duration: 53, description: ""}
// 2: PerformanceServerTiming {name: "app", duration: 47.2, description: ""}

Specifications

Specification	Status	Comment
Server TimingThe definition of 'PerformanceServerTiming' in that specification.	Working Draft	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`PerformanceServerTiming`	Chrome Full support 65	Edge Full support ≤79	Firefox Full support 61	IE No support No	Opera Full support 52	Safari ?	WebView Android Full support 65	Chrome Android Full support 65	Firefox Android Full support 61	Opera Android Full support 47	Safari iOS ?	Samsung Internet Android Full support 9.0
`description` Experimental'	Chrome Full support 65	Edge Full support ≤79	Firefox Full support 61	IE No support No	Opera Full support 52	Safari ?	WebView Android Full support 65	Chrome Android Full support 65	Firefox Android Full support 61	Opera Android Full support 47	Safari iOS ?	Samsung Internet Android Full support 9.0
`duration` Experimental'	Chrome Full support 65	Edge Full support ≤79	Firefox Full support 61	IE No support No	Opera Full support 52	Safari ?	WebView Android Full support 65	Chrome Android Full support 65	Firefox Android Full support 61	Opera Android Full support 47	Safari iOS ?	Samsung Internet Android Full support 9.0
`name` Experimental'	Chrome Full support 65	Edge Full support ≤79	Firefox Full support 61	IE No support No	Opera Full support 52	Safari ?	WebView Android Full support 65	Chrome Android Full support 65	Firefox Android Full support 61	Opera Android Full support 47	Safari iOS ?	Samsung Internet Android Full support 9.0
`toJSON` Experimental'	Chrome Full support 65	Edge Full support ≤79	Firefox Full support 61	IE No support No	Opera Full support 52	Safari ?	WebView Android Full support 65	Chrome Android Full support 65	Firefox Android Full support 61	Opera Android Full support 47	Safari iOS ?	Samsung Internet Android Full support 9.0

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.