Lightbox vs Popups

Does anyone please know if using Lightbox to display images on a website will make the website a much smaller file size than using popups?

This really isn't an issue of 'website size' I don't think. Lightbox (and its variants) actually add a little bit of byte size to the web pages, because they require extra coding whereas an anchor tag with a target attribute is lighter.

However I think Lightbox is a preferred solution to a Popup, because people have blockers and really hate popups. Lightbox works better and I think it is used enough that a lot of users recognize what they are seeing and know its safe.