Hello, thank you for your valuable review. :) It's the same when applied to Swiper js~! const swiper = new Swiper('.swiper-container', { effect: 'fade', speed: 0, navigation: { nextEl: '.swiper-button-next', prevEl: '.swiper-button-prev', }, on: { slideChange: function () { var thisSlide = $('.swiper-container').find('.swiper-slide').eq(this.activeIndex); ggangImgEffect(thisSlide, this.activeIndex); } } }); You can use the slideChange callback function that is called when the slide changes like this. :)