Slide freezes with images

[leodidier14]

Hello !

I am currently using the swiper js library. I have made slides that are vertically linked. Each slide takes the size of the screen with a baground-image. Each time I refresh my page, I got few freezes/lags. It only happens the first time I get to it after a refresh, after that it's all flowing.
I already compress my image so i dont think this is the problem.

have you an idea ?