PerformanceResourceTiming.decodedBodySize

The decodedBodySize read-only property returns the size (in octets) received from the fetch (HTTP or cache) of the message body, after removing any applied content-codings. If the resource is retrieved from an application cache or local resources, it returns the size of the payload after removing any applied content-codings.

Note: This feature is available in Web Workers.

Syntax

resource.decodedBodySize;

Return value

The size (in octets) received from the fetch (HTTP or cache) of the message body, after removing any applied content-codings.

Example

The following example, the value of the size properties of all "resource" type events are logged.

function log_sizes(perfEntry){
  // Check for support of the *size properties and print their values
  // if supported.
  if ("decodedBodySize" in perfEntry)
    console.log("decodedBodySize = " + perfEntry.decodedBodySize);
  else
    console.log("decodedBodySize = NOT supported");

  if ("encodedBodySize" in perfEntry)
    console.log("encodedBodySize = " + perfEntry.encodedBodySize);
  else
    console.log("encodedBodySize = NOT supported");

  if ("transferSize" in perfEntry)
    console.log("transferSize = " + perfEntry.transferSize);
  else
    console.log("transferSize = NOT supported");
}
function check_PerformanceEntries() {
  // Use getEntriesByType() to just get the "resource" events
  var p = performance.getEntriesByType("resource");
  for (var i=0; i < p.length; i++) {
    log_sizes(p[i]);
  }
}

Specifications

Specification Status Comment
Resource Timing Level 2
The definition of 'decodedBodySize' in that specification.
Working Draft Initial definition.

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
decodedBodySizeChrome Full support 54Edge Full support 17Firefox Full support 45IE No support NoOpera Full support 41Safari No support NoWebView Android Full support 54Chrome Android Full support 54Firefox Android Full support 45Opera Android Full support 41Safari iOS No support NoSamsung Internet Android Full support 6.0

Legend

Full support
Full support
No support
No support