Search engines gives more priority to the sites that load faster and have less server response time. Whatever the quality and dedicated servers you choose for hosting, it is necessary to use compressed images on the site. Optimize images will be showing as the error message under "Should fix" category when you test the speed using Google PageSpeed tool. 

High end content management systems like WordPress has many image compression plugins to optimize your images for search engines. But many other site builders like Weebly, Wix, etc. don't have the option to compress your images. You also need licensed software like Photoshop to create compressed images on your local computer before uploading to your site.

For all those who are struck, here we have a free bulk image compressor tool to optimize all your images. You can upload 10 files at time and get the details of the size saved due to compression. Each image should be less than 2MB in size and the compressed images can be downloaded to your local disk without any registration. At this moment the image compressor tool supports PNG and JPEG formats.

Also note, each image on a page sends separate HTTP request to server. Hence it is a good idea to host all images in a separate subdomain to load the images in parallel to increase the speed.