There are many ways to optimize images for the web. Below, you’ll find a few methods you can use to further optimize your images before uploading. You should ALWAYS optimize your images for page loading.
Swift Performance’s premium version has both caching and image optimization covered. We’ve had great experience with the performance/caching side of the plugin over the rest of the caching plugins out there. It’s less bloated, and really easy to setup and use. This eliminates having both a caching plugin and an image optimization plugin. The image optimization is good at keeping things at lower sizes, while still keeping your images quality the same, it does a good job at both things, but the image sizes are a little higher than a dedicated plugin would be. Either way, you can’t go wrong with this option since it’s doing the job of two plugins.
Shortpixel is one of the new kids on the block in terms of popularity. It seems to have one of the highest optimization reduction rates while also keeping the same great quality with your images. The best thing is that it does it all on it’s own once installed. This plugin like Swift, is a premium plugin and requires WordPress. You’ll likely get better results with a dedicated plugin like this one to do the job, but this one is only for image optimization on it’s own.