Post-loading : check if an image is in the browser cache

Question

Short version question : Is there navigator.mozIsLocallyAvailable equivalent function that works on all browsers, or an alternative?

Long ve

Answer 1

In 2017, Resource Timing API can help you check this using PerformanceResourceTiming.transferSize property. This property shall return non-zero transfer size when it is downloaded from server (not cached) and returns zero if fetched from a local cache.

Reference : https://developer.mozilla.org/en-US/docs/Web/API/PerformanceResourceTiming/transferSize