SkeletonJS is a lightweight JavaScript library that converts HTML elements into animated skeleton loaders. It’s designed to help you create visually appealing loading placeholders with minimal configuration. SkeletonJS uses CSS custom properties and a default shimmer animation to display skeleton states for your content.
Simple CSS-based Skeleton Loader:
Easily convert HTML elements to skeleton loaders using CSS classes and custom properties.
Customization Options:
Customize the background color, border radius, animation duration, animation type, and gradient background via inline styles or data attributes.
Dynamic Cloning:
Use the data-skeletons-count attribute to clone an element multiple times, useful for simulating lists or grids of content.
Static Loader Option:
For static content, simply add the .skeletonJS class and configure CSS variables—no JavaScript initialization required.
Image Replacement:
Automatically replaces <img> tags with <span> elements to hide the actual image content and display the skeleton style instead.
Clone the repository or download the source code. Then, build the project using your preferred bundler (e.g., Webpack). The compiled files (CSS and JS) will be located in the dist folder.
git clone https://github.com/deepansumor/SkeletonJS.git
cd SkeletonJS
npm install
npm run build
<script src="../dist/skeleton.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/deepansumor/SkeletonJS@latest/dist/skeleton.min.js"></script>
Include the generated CSS and JS files in your HTML. Then, add the .skeletonJS class along with any custom properties or data attributes.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<title>SkeletonJS Dynamic Example</title>
<!-- Link the SkeletonJS CSS -->
<link rel="stylesheet" href="../dist/skeleton.css" />
<!-- Load SkeletonJS script (synchronously or with defer as needed) -->
<script src="../dist/skeleton.js"></script>
</head>
<body>
<h1>SkeletonJS Dynamic Example</h1>
<!-- Dynamic Skeleton: clones itself based on data-skeletons-count -->
<div
class="skeletonJS"
data-skeletons-count="10"
style="--skeleton-background-color: #e0e0e0;
--skeleton-border-radius: 4px;
--skeleton-animation-duration: 1s;
--skeleton-animation-type: shimmer;
--skeleton-animation-background: rgba(255,255,255,0.2);"
>
<h2>Title</h2>
<p>This is a paragraph that will be skeletonized.</p>
<!-- The image will be replaced by a span to hide its content -->
<img
src="https://plus.unsplash.com/premium_photo-1681487548276-48a2c640ade9?q=80&w=2070&auto=format&fit=crop"
alt="Placeholder image"
style="width: 100%; height: 200px;"
/>
</div>
<!-- Initialize SkeletonJS -->
<script>
// This will convert all elements with the .skeletonJS class into skeleton loaders.
SkeletonJS.init(document.querySelectorAll(".skeletonJS"));
</script>
</body>
</html>
For static content, simply add the .skeletonJS class and define your CSS custom properties. No JS initialization is required.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<title>SkeletonJS Static Example</title>
<!-- Link the SkeletonJS CSS -->
<link rel="stylesheet" href="../dist/skeleton.css" />
</head>
<body>
<h1>SkeletonJS Static Example</h1>
<!-- Static Skeleton: purely CSS-based -->
<div
class="skeletonJS"
style="--skeleton-background-color: #e0e0e0;
--skeleton-border-radius: 4px;"
>
<h2>Title</h2>
<p>This is a paragraph that will be skeletonized.</p>
<div style="width: 100px; height: 100px;"></div>
</div>
</body>
</html>
SkeletonJS.init(elements, options)Initializes SkeletonJS on one or more target elements.
elements: A query selector string, an HTMLElement, a NodeList of HTMLElements, or an array of HTMLElements.options (optional): An object conforming to the SkeletonOptions interface. Options provided here override any data attributes on the elements.interface SkeletonOptions {
backgroundcolor?: string; // Background color of the skeleton (e.g., "#e0e0e0")
borderRadius?: string; // Border radius (e.g., "4px")
color?: string; // Text color (generally set to transparent)
animationDuration?: string; // Animation duration (e.g., "1s")
animationType?: string; // Animation type (default: "shimmer")
animationBackground?: string; // Animation gradient background (e.g., "rgba(255,255,255,0.2)")
}
Style Injection:
SkeletonJS injects a CSS <style> element containing the base skeleton styles and shimmer animation into the document head (once per page load).
Custom Properties:
CSS custom properties (variables) are used to allow easy customization of the skeleton loader’s appearance.
Data Attributes & Options:
Options can be specified via data attributes on HTML elements or passed programmatically when initializing SkeletonJS.
Dynamic Cloning:
If an element has the data-skeletons-count attribute, SkeletonJS will clone the element the specified number of times to simulate multiple loading items.
Image Replacement:
Any <img> elements inside a skeleton loader are replaced with <span> elements, ensuring that the skeleton appearance is maintained.
SkeletonJS uses Webpack for bundling. To build the project, run:
npm run build
This will compile the TypeScript and LESS files into the dist directory.
To test the library locally, open one of the example HTML files in your browser or set up a local server.
This project is licensed under the MIT License.
Deepansu Mor
GitHub: deepansumor