What is the best way to optimize images on the site now?

Question

Images

Laravel site. Online comic book reader. There are a lot of cards.
As far as I know, tinypng optimizes well and is almost lossless, but it is paid. And since there are a lot of pictures, you will have to pay a lot too.
Maybe there are free ones. It is desirable that the images are optimized when uploading to the site.
You also need to enable gzip archiving on the server. I compressed the picture in gzip on the PC, it did not become smaller. How effective is this method?