Resource size
The decodedBodySize, encodedBodySize, and transferSize properties of the PerformanceResourceTiming API reports the size of resources loaded.
Status
Baseline Widely Available (since 2025-09-27)
MDN documentation
Specifications
- Resource Timing (#dom-performanceresourcetiming-decodedbodysize), from Web Performance Working Group (W3C).
- Resource Timing (#dom-performanceresourcetiming-encodedbodysize), from Web Performance Working Group (W3C).
- Resource Timing (#dom-performanceresourcetiming-transfersize), from Web Performance Working Group (W3C).
Browser support
- Chrome 54 Released on 2016-10-12
- Chrome Android 54 Released on 2016-10-19
- Edge 17 Released on 2018-04-30
- Firefox 45 Released on 2016-03-08
- Firefox for Android 45 Released on 2016-03-08
- Safari 16.4 Released on 2023-03-27
- Safari on iOS 16.4 Released on 2023-03-27
View as JSON | Edit this feature | Report an issue | Web-features entry: source, dist