What is Lossless and Lossy?

Lossless

Images will not lose any quality, they will be 100% same as the original. You can expect on average 5% - 15% savings for JPEG and 15% - 25% for PNG files.

Lossy

You sacrifice a small amount of the image quality (usually not noticeable to the human's eyes) for very large compression. You can expect on average 15% - 30% savings for JPEG and 40% - 50% for PNG files at quality level 90%.

We recommend using Lossy with image quality set at 85% to save more image size but still retain the best image quality

Please don't attempt to select Lossy and set the image quality < 50%, your images might look bad and blurry