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 | Status | Comment |
---|---|---|
Resource Timing Level 2 The definition of 'transferSize' in that specification. |
Working Draft | Initial definition. |
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
transferSize | Chrome Full support 54 | Edge Full support 17 | Firefox Full support 45 | IE No support No | Opera Full support 41 | Safari No support No | WebView Android Full support 54 | Chrome Android Full support 54 | Firefox Android Full support 45 | Opera Android Full support 41 | Safari iOS No support No | Samsung Internet Android Full support 6.0 |
Legend
- Full support
- Full support
- No support
- No support