Why logo carousel lazyload left blank whitespace under sliders and the lazy spinner + layout CSS tweak that removed gaps

A common issue web developers face when implementing logo carousels with lazy loading is the unexpected appearance of blank whitespace beneath the sliders. This can lead to layout instability, poor visual experience, and confusing user interface behavior. Understanding how and why this happens—and implementing a reliable fix—is essential for delivering smooth and performant web experiences.

TL;DR

Lazy loading in logo carousels often delays image injection, which can cause unexpected gaps or whitespace beneath sliders. This issue usually occurs because placeholder elements don’t have proper dimensions set until images are fully downloaded. The addition of a smart spinner plus a small but crucial CSS tweak can stabilize the layout by preserving the height and preventing elements below the carousel from jumping. The fix ensures consistency and eliminates visual flicker during initial load.

Why Logo Carousels Create Blank Space When Lazy Load Is Enabled

Lazy loading is an efficient technique that improves page load speed by deferring image loading until they are needed. However, when applied to logo sliders or image carousels, it often comes with the side effect of blank vertical gaps showing up beneath the carousel area. This happens primarily because the DOM initially renders the carousel’s layout without knowing the final dimensions of the images to be loaded. Until each image finishes loading, the container may collapse, leading to the unpleasant jump or flicker of layout.

This is usually seen as extra padding or margin-like space beneath the carousel, making the entire page feel unstable or incomplete at first render. The root causes include:

• Image dimensions are unknown during the initial render
• CSS not enforcing consistent heights for slider items or wrappers
• No defined fallback or placeholder height for lazy-loaded elements

Additionally, certain carousel libraries or plugins may dynamically inject DOM elements that are invisible or lack minimum height until their images load. When these images are lazy loaded and a spinner is used as a visual loading indicator, the spinner itself may inherit 0 height or not vertically center, adding to the problem.

The Role of the Spinner Component

Many lazy load implementations add a spinner inside carousel items while the image is loading. But if not properly styled or dimensioned, the spinner merely shows up as a tiny icon in an otherwise empty and collapsed space, failing to preserve vertical height. This makes it appear like the slider section hasn’t loaded at all, further confusing users.

An effective approach to solve this is by giving each lazy-loaded image container a fixed aspect ratio or height based on anticipated image dimensions. While the image is loading, the spinner fills this container, maintaining minimum height and preventing layout shifting.

The CSS Fix: Enforcing Height Stability With Layout Tweaks

A simple, yet powerful CSS solution involves explicitly defining the dimensions of the carousel and its children. Here are some best practices:

• Wrap each logo/image in a flexbox container with vertical alignment set
• Set a consistent min-height on the image or placeholder elements
• Use object-fit: contain; and enforce max-width and max-height rules
• Implement skeleton loaders or proportional padding trick (padding-bottom hack)

Here is an example CSS snippet to illustrate a solution:

.carousel-item {
  min-height: 100px;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.carousel-item img {
  max-width: 100%;
  max-height: 100px;
  object-fit: contain;
}

This layout tweak ensures that whether the image is loading or already loaded, the overall structural height of the slider items remains the same. As a result, no unexpected blank space appears under the carousel, even during the lazy load phase.

Why Fixed Heights Matter in Responsive Layouts

One might argue that fixed heights are anti-responsive. However, for elements like logo sliders where the image height rarely changes significantly across breakpoints, it is acceptable—and often preferable—to use fixed or min-heights that emulate the typical logo size. You can further use media queries to adjust the height dynamically across device widths if needed.

Without such constraints, responsive sliders with dynamic content can cause reflows or instability as images render, especially when JavaScript-based resizing is in play. Applying well-structured CSS rules mitigates these issues by preserving the “shell” of each slider item before its content arrives.

Advanced: Using IntersectionObserver and Layout Sentry Classes

In more complex frontend setups, you can combine lazy loading with the IntersectionObserver API. This gives more control over when an image starts loading and allows toggling CSS classes that prepare the layout.

For example:

• Add a .loading class while the image is loading
• Switch to .loaded once the image loads and fill the container

This approach could work as follows:

.loading::after {
  content: url('/spinner.gif');
  display: block;
  height: 100px;
  width: 100px;
  margin: 0 auto;
}

With this technique, not only does the whitespace issue get solved, but it also provides visual feedback to users waiting for images to render, enhancing UX.

Conclusion

Logo carousel blanking or whitespace issues during lazy load are widespread among modern web interfaces, especially with performance-focused plugins and sliders. Without layout feedback or defined dimensions, browsers simply cannot reserve space for elements that haven’t yet entered the DOM. Using a combination of CSS layout tweaks—such as hardcoded min-height, smart spinners, and container aspect ratios—resolves this issue entirely. Results include smoother experiences, no flickering, and a cleaner visual hierarchy.

Frequently Asked Questions (FAQ)

• Q: Why is there empty space under my logo carousel?
  A: This typically happens because lazy-loaded images haven’t been given fixed dimensions, so the browser collapses the container’s height until the images fully load.
• Q: Does the lazy load spinner help prevent whitespace?
  A: Only if it is properly styled to preserve height. Otherwise, it just appears in a collapsed area and does not fix the layout gap.
• Q: How can I fix the layout jump when images load?
  A: Set a consistent min-height or use predictable aspect ratios in CSS to ensure the container retains space before the image loads.
• Q: What is the CSS ‘padding-bottom’ trick?
  A: It’s a way to preserve aspect ratio by applying padding as a percentage of the element width, allowing the container to maintain available space before content loads.
• Q: Can this fix be used on mobile?
  A: Yes. With proper media queries and responsive units, this approach works well on all screen sizes.