When does the browser load event occur?

Question

I wonder when the download event occurs in the browser? Is this when he gets the header information?

Answer 1

onload starts after loading the entire document, images and all.

Some browsers, such as Firefox, also have content loading events that fire after the HTML file is delivered, but before external files, such as images, are downloaded.

Answer 2

onload happens when all data is loaded, including all css, javascript files and images.