<img src="urlToFile"> is blocking the application until image loaded


Im relative new in web developing. But i thought when i use the img-tag with a url the image is loading asynchrone in a non-blocking way.

The whole application is freezing for the time the image is loading.

Can someone help. I tried different things. Like loading the image in javascript. He is always blocking.

I use “Image Data URI’s” as urls. Maybe its important!?