How to Center OwlCarousel Items When There Are Less Than 4 Items: Responsive Fix for OwlCarousel 1.3.3

Table of Contents#

Understanding the Problem
Prerequisites
Step 1: Initialize OwlCarousel with Base Settings
Step 2: Identify the Root Cause
Step 3: Fix with CSS & JavaScript
- 3.1: Add Custom CSS for Centering
- 3.2: Use JavaScript to Detect Item Count & Viewport
Testing & Troubleshooting
Conclusion
References

Understanding the Problem#

By default, OwlCarousel 1.3.3 calculates the width of the carousel wrapper (.owl-wrapper) based on the number of items and the "items per slide" setting. When the total number of items is less than the configured count (e.g., 3 items with items: 4), the wrapper retains a fixed width, forcing items to align left. This results in empty space on the right, as shown below:

Example of the Issue:

4 items: Items span the full carousel width (correct).
3 items: Items left-align with empty space on the right (problem).

Prerequisites#

Before starting, ensure you have:

A working installation of OwlCarousel 1.3.3 (CSS and JS files included).
jQuery (required for OwlCarousel 1.3.3).
Basic knowledge of HTML, CSS, and JavaScript.
A code editor (e.g., VS Code) and browser dev tools (for testing).

Step 1: Initialize OwlCarousel with Base Settings#

First, set up your carousel with the desired "items per slide" and responsive breakpoints. For this guide, we’ll use items: 4 on desktop, items: 2 on tablets, and items: 1 on mobile.

HTML Structure#

<div class="owl-carousel" id="myCarousel">  
  <div class="owl-item">Item 1</div>  
  <div class="owl-item">Item 2</div>  
  <div class="owl-item">Item 3</div>  
  <!-- Add/remove items to test (e.g., 1, 2, 3, or 4 items) -->  
</div>

Initialize OwlCarousel#

Include the OwlCarousel CSS/JS files and initialize the carousel:

<!-- OwlCarousel CSS -->  
<link rel="stylesheet" href="owl.carousel.css">  
<link rel="stylesheet" href="owl.theme.css">  
 
<!-- jQuery (required) -->  
<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>  
 
<!-- OwlCarousel JS -->  
<script src="owl.carousel.min.js"></script>  
 
<script>  
  $(document).ready(function() {  
    $("#myCarousel").owlCarousel({  
      items: 4, // Default items per slide (desktop)  
      responsive: {  
        0: { items: 1 },   // Mobile: 1 item  
        768: { items: 2 }, // Tablet: 2 items  
        992: { items: 4 }  // Desktop: 4 items  
      },  
      navigation: true, // Show next/prev buttons  
      pagination: false // Hide pagination dots (optional)  
    });  
  });  
</script>

Step 2: Identify the Root Cause#

OwlCarousel 1.3.3 uses a wrapper div (.owl-wrapper) to contain carousel items (.owl-item). By default, .owl-wrapper has a fixed width calculated as:
width = (item width + margin) * number of items.

When there are fewer items than the "items per slide" count, this fixed width is smaller than the carousel container, causing .owl-wrapper to left-align (due to float: left in OwlCarousel’s CSS).

To confirm, inspect the carousel with browser dev tools:

The .owl-wrapper element will have float: left and a fixed width.
Items inside will align left, leaving empty space on the right.

Step 3: Fix with CSS & JavaScript#

To center items when there are fewer than the "items per slide" count, we’ll combine:

CSS adjustments to center .owl-wrapper when needed.
JavaScript to detect item count and viewport size, then apply centering dynamically.

3.1: Add Custom CSS for Centering#

First, add CSS to center .owl-wrapper when fewer items are present. We’ll target a custom class (e.g., center-items) to avoid affecting full carousels.

/* Custom CSS to center owl-wrapper */  
#myCarousel.center-items .owl-wrapper {  
  float: none !important; /* Override OwlCarousel's default float: left */  
  margin: 0 auto !important; /* Center the wrapper */  
  width: auto !important; /* Let the wrapper width adjust to items */  
}  
 
/* Optional: Adjust item spacing for better centering */  
#myCarousel .owl-item {  
  margin: 0 10px; /* Add horizontal margin between items */  
}

3.2: Use JavaScript to Detect Item Count & Viewport#

Next, we need to:

Count the total number of carousel items.
Determine the current "items per slide" based on the viewport (using OwlCarousel’s responsive settings).
Add the center-items class to the carousel if total items < items per slide.
Update dynamically on window resize (for responsive behavior).

Step 3.2.1: Define Responsive Breakpoints#

Mirror the responsive settings from your carousel initialization to determine "items per slide" at different viewport widths:

// Define responsive breakpoints (matches OwlCarousel config)  
const responsiveBreakpoints = [  
  { width: 0, items: 1 },    // Mobile: 0px+  
  { width: 768, items: 2 },  // Tablet: 768px+  
  { width: 992, items: 4 }   // Desktop: 992px+  
];

Step 3.2.2: Function to Get Current Items Per Slide#

Create a function to return the "items per slide" for the current viewport width:

function getCurrentItemsPerSlide() {  
  const windowWidth = $(window).width();  
  let itemsPerSlide = 1; // Default to mobile  
 
  // Check breakpoints from largest to smallest  
  for (let i = responsiveBreakpoints.length - 1; i >= 0; i--) {  
    if (windowWidth >= responsiveBreakpoints[i].width) {  
      itemsPerSlide = responsiveBreakpoints[i].items;  
      break;  
    }  
  }  
  return itemsPerSlide;  
}

Step 3.2.3: Function to Toggle Centering Class#

Create a function to check item count vs. current items per slide and apply/remove center-items:

function toggleCenterItemsClass() {  
  const $carousel = $("#myCarousel");  
  const totalItems = $carousel.find(".owl-item").length;  
  const itemsPerSlide = getCurrentItemsPerSlide();  
 
  // Add 'center-items' class if total items < items per slide  
  if (totalItems < itemsPerSlide) {  
    $carousel.addClass("center-items");  
  } else {  
    $carousel.removeClass("center-items");  
  }  
}

Step 3.2.4: Trigger the Function#

Run toggleCenterItemsClass() on page load and whenever the window resizes:

$(document).ready(function() {  
  // Initialize OwlCarousel (from Step 1)  
  $("#myCarousel").owlCarousel({  
    items: 4,  
    responsive: {  
      0: { items: 1 },  
      768: { items: 2 },  
      992: { items: 4 }  
    },  
    navigation: true,  
    pagination: false  
  });  
 
  // Trigger centering logic on load  
  toggleCenterItemsClass();  
 
  // Update on window resize (with debounce to optimize performance)  
  let resizeTimer;  
  $(window).resize(function() {  
    clearTimeout(resizeTimer);  
    resizeTimer = setTimeout(toggleCenterItemsClass, 100); // Adjust delay as needed  
  });  
});

Testing & Troubleshooting#

Test Scenarios#

Fewer than 4 items on desktop: 1, 2, or 3 items should center.
Exactly 4 items on desktop: No centering (items span full width).
Tablet view (768px): 1 item should center (since items: 2 is the threshold).
Mobile view (0px): 1 item should span full width (no centering needed).

Common Issues & Fixes#

center-items class not added: Ensure totalItems and itemsPerSlide are calculated correctly (use console.log(totalItems, itemsPerSlide) to debug).
OwlCarousel CSS overriding custom styles: Use !important in your CSS (as shown in Step 3.1) to prioritize custom rules.
Jumpy resizing: The resizeTimer with setTimeout reduces excessive function calls during resizing.
Items overlapping: Adjust .owl-item margin in CSS to add spacing between items.

Conclusion#

By combining CSS adjustments to center the carousel wrapper with JavaScript logic to detect item count and viewport size, you can ensure OwlCarousel 1.3.3 items center beautifully when fewer than the "items per slide" count are present. This fix works across devices and dynamically updates on resize, making your carousel responsive and visually consistent.

While OwlCarousel 2.x offers more built-in features, this solution breathes new life into legacy projects using 1.3.3.