Web pages with large and uncompressed image files are going to load more slowly than pages with correctly-sized and properly-optimized images. While there’s hundreds of apps available to resize and compress image files, few (if any) are easier to use than Bzzt! Image Editor.
Bzzt! Image Editor is a small Windows app that makes it super-easy to create web-friendly images. Once you’ve set your output size and quality preferences, just drag-and-drop the files you want to optimize onto the UI and Bzzt! will process them instantly. You can even process entire folders full of images at a time.