I run into many websites that still have images that are too large in size, which reduces the page load time. You want your images as small as possible for this reason, and also as many web content management systems have limits to how much data you can store.
In this video from the Graphic Society, they cover how to optimise images for the web using Pixlr Editor. The free software, which can be run directly from any computer without downloading or even logging in, can be found here: https://pixlr.com/e/
Enjoy!
