Optimizing your images by compressing and resizing them may reduce the sizes of the images by a great extent, decreasing the page sizes and thus improving page loading performance on your blog. You may use online image resizing and compressing tools as well as their offline counterparts.

Make sure the images that you upload in WordPress are already optimized, but even if you don’t have already optimized images to upload, you can use a plugin to optimize and reduce the sizes of uploaded images automatically.

You can also add proper image tags to images in your posts to help them rank better in image searches. You can also include additional keywords through alt tags in your posts.