Images always take so much of space on your webpage and because of that your visitor will have to suffer from the page loading problems. Always compress the image before uploading them onto the server. Some of the Image compressors are provided below and it is very easy to use them.
Last two options are online compressors where you need to upload the file on to the server and the compressed version will be ready to download from that. It will not take more than 1 minutes to compress a file. So remember, always compress the image file before moving to the server. You should also compress the JavaScripts present on your server.