Image file size vs. visible image size?

Replies: 3

Hello. I am using Elementor which offers the following resizing options of uploaded images:
Thumbnail 150×150
Medium 300×300
Medium-Large 768×0
Large 1024×1024
Full
Custom

I have many images that I took on my phone that have the dimensions of 2432×4320, and of course I will reduce their sizes before uploading, but I don’t know by how much I should if Elementor has the resizing options above.

How small should I optimize the images before uploading?

And if using the Elementor or WordPress resizing options to reduce the visible image size for site visitors, do these resizing options also reduce file sizes for quicker loading?

Thanks!
Jeff