In general, there is this:

<img src='big_img.jpg'>

The picture itself is loaded sooo long, since the size of more than 4MB I want to put a progress bar. Question: how to find out by how many percent the big_img.jpg file is downloaded?

ps: fancybox has a similar experience, but it’s not clear how it’s implemented: (

    1 answer 1

    In this article , at the very bottom, there is your case. Retell here - I do not see much point.