This is a program that compresses one or more PNG pictures without ever resizing them. As soon as you add your PNG pictures in the input area, the program reduces their color palette and re-encodes them, so each output keeps the exact width and height of the input. In the options, you can adjust the compression level, ask for a maximum output size, and find the old and new picture file sizes.
Keep PNG for transparency; otherwise JPG/WebP may be smaller.
Depends on level — often near-lossless.
Upload in batches; huge sets fit scripts better.