Debugging Slick Slider: The Ghost Slide Mystery

Debugging can sometimes feel like an epic quest, and recently, I embarked on one that had me chasing ghost slides in Slick Slider. Everything worked perfectly on desktop and mobile emulators, but on a real mobile device, removed images still left blank slides in the carousel. Here's how I cracked the case and fixed it for good.

The Problem: Ghost Slides in Slick Slider

The goal was simple: remove all lifestyle images (identified by a regex pattern) from a product page slider and reinitialize Slick so that it properly adjusted.

• On desktop & emulators → Everything worked as expected.
• On real mobile devices → The images disappeared, but the slides remained, holding empty space.

The code was doing this:

1. Finding all images matching a pattern like LS-1234.jpg.
2. Removing them from the DOM.
3. Calling slickRemove on matching slides.
4. Destroying and reinitializing Slick Slider.

Yet, on mobile, Slick refused to let go of the ghost slides.

Debugging the Issue

After inspecting .slick-track, I realized:

• The slides still existed in the DOM, but were empty.
• slickRemove wasn’t fully updating Slick’s internal state.
• Even after unslick(), reinitializing didn't remove the ghost slides.

What Didn’t Work

❌ Just using .remove() – The elements were gone, but Slick still thought they were there.
❌ Using .slickRemove(index) – This worked sometimes, but wasn’t reliable on mobile.
❌ Calling .slick(‘setPosition’) – Didn’t clear out the extra slides.

The Fix: A Multi-Step Cleanup

To fully remove unwanted slides and ensure Slick resets correctly, I used a three-step process:

1️⃣ Remove Images AND Their Wrappers

Instead of only removing <img>, I targeted .slick-slide elements and ensured they were properly detached.

const removeLifestyleImages = async (container) => {
  if (!container) return;
 
  const regex = /(LS-\d+|LS\d+|alt\d+|alt-\d+|lifestyle\d+)$/i;
  container.querySelectorAll('img').forEach((img) => {
    if (regex.test(img.src)) {
      let wrapper = img.closest('.slick-slide');
      if (wrapper) {
        wrapper.remove();
      }
    }
  });
};

2️⃣ Manually Remove Any Remaining Empty Slides

After slickRemove failed to remove some slides, I double-checked for orphaned .slick-slide elements and deleted them manually.

const manuallyRemoveExtraSlides = () => {
  document.querySelectorAll('.slick-slide').forEach((slide) => {
    if (!slide.innerHTML.trim()) {
      slide.remove();
    }
  });
};

3️⃣ Destroy and Fully Reinitialize Slick

To force a proper refresh, I ensured Slick was completely destroyed and rebuilt with a delay.

const resetSlick = () => {
  const slickContainer = $('.product-image');
 
  if (slickContainer.hasClass('slick-initialized')) {
    slickContainer.slick('unslick');
  }
 
  setTimeout(() => {
    slickContainer.slick({
      infinite: true,
      slidesToShow: 1,
      slidesToScroll: 1,
      dots: true,
      arrows: false,
    });
  }, 300);
};

Final Working Solution

The full fix now follows these steps:

1. Remove all images & wrappers.
2. Ensure extra .slick-slide elements are cleaned up.
3. Destroy and reinitialize Slick after modifications.

const hideLifestyleImages = async () => {
  const productMedia = document.querySelector('.product.media');
  await removeLifestyleImages(productMedia);
  manuallyRemoveExtraSlides();
  resetSlick();
};
 
hideLifestyleImages();

Lessons Learned

🔹 Desktop ≠ Mobile. Always test on real devices—emulators don’t always mimic behavior perfectly.
🔹 Slick Slider needs extra nudging when dynamically modifying its slides.
🔹 Always re-check the DOM after removing elements—what looks gone may still be lurking in .slick-track.

This debugging journey was a perfect example of why real-world testing matters. Now, no more ghost slides haunting my product pages! 👻