PerformanceResourceTiming.transferSize
The transferSize
read-only property represents the size
(in octets) of the fetched resource. The size includes the response header fields plus
the response payload body (as defined by RFC7230).
Note: This feature is available in Web Workers
If the resource is fetched from a local cache, or if it is a cross-origin resource, this property returns zero.
Syntax
resource.transferSize;
Return value
A number
representing the size (in octets) of the fetched resource. The
size includes the response header fields plus the response payload
body (RFC7230).
Example
The following example, the value of size properties of all "resource
"
type
events are logged.
function log_sizes(perfEntry){
// Check for support of the PerformanceEntry.*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 |
---|
Resource Timing Level 2 # dom-performanceresourcetiming-transfersize |
Browser compatibility
BCD tables only load in the browser