Jigidi revised its guidelines in 2018 and now enforces its rules against bullying and trolling. (If you feel you are being bullied, do report it to Jigidi. They can't monitor all comments.) If you tried Jigidi before and left because of other users' comments, go back and try again. The site is greatly improved. Do read the new guidelines, which address technological changes as well as behavior guidelines.
Jigidi is the best online jigsaw puzzle site I have found and I've tried many. The interface is smooth, not laggy or jerky; the pieces are shaped like "real" jigsaw puzzle pieces; and there is a never-ending supply of new puzzles in different sizes. The site is free to users who are willing to see advertisements, and if you don't want ads, you can become a Jigidi Plus member for US $18/year.