State & Feedback Animation — Reference
Glow
The Glow is a pure-CSS loading animation that a soft pulsing glow effect that oscillates brightness and box-shadow intensity. Great for ambient state indicators, active-status badges, or highlighting elements with a warm luminous aura. It requires no JavaScript, runs entirely on the GPU via CSS transforms, and communicates application state clearly without blocking the browser's main thread.
When to use the Glow
- Active state indicators, premium plan highlights, and status badges
- Notification badges, live status dots, and attention anchors
- Communicating async operations like API fetches or file uploads
- Replacing blank screens during server-side rendering hydration
- Inline loading states within tables, feeds, or infinite-scroll lists
Performance characteristics
- GPU-accelerated — uses CSS transform and opacity so compositing happens off the main thread
- Zero JavaScript dependency in most configurations — no framework, no bundler required
- Approximately 60 fps on any device that supports CSS animations (Chrome 43+, Firefox 16+, Safari 9+)
- Typically under 2 KB of CSS — negligible impact on Largest Contentful Paint (LCP)
How it compares
Unlike JavaScript spinners rendered with requestAnimationFrame loops, the Glow runs on the GPU compositor thread, meaning a blocked main thread — caused by heavy data processing or framework hydration — will not freeze or jank the animation.
Compared to GIF loading indicators, this CSS approach uses roughly 95% less bandwidth and scales crisp at every pixel density, including HiDPI and Retina displays.
Source code
CSS
.glow {
width: 64px; height: 64px;
background: #f59e0b;
border-radius: 12px;
box-shadow: 0 0 15px #f59e0b;
animation: glow 1.5s ease-in-out infinite;
}
@keyframes glow {
0%, 100% { box-shadow: 0 0 15px #f59e0b; filter: brightness(1); }
50% { box-shadow: 0 0 40px #f59e0b; filter: brightness(1.3); }
}
body { margin: 0; min-height: 100vh; display: flex; align-items: center; justify-content: center; background: #0f0f0f; }HTML
<div class="glow"></div>Full source
<!DOCTYPE html>
<html>
<head>
<style>
.glow {
width: 64px; height: 64px;
background: #f59e0b;
border-radius: 12px;
box-shadow: 0 0 15px #f59e0b;
animation: glow 1.5s ease-in-out infinite;
}
@keyframes glow {
0%, 100% { box-shadow: 0 0 15px #f59e0b; filter: brightness(1); }
50% { box-shadow: 0 0 40px #f59e0b; filter: brightness(1.3); }
}
body { margin: 0; min-height: 100vh; display: flex; align-items: center; justify-content: center; background: #0f0f0f; }
</style>
</head>
<body>
<div class="glow"></div>
</body>
</html>Frequently asked questions
How do I add the Glow to my project?
Copy the full source code from the code block on this page. Paste the <style> block into your stylesheet (or a <style> tag in your HTML head) and the HTML markup into your template. No npm install or build step is required — the animation is self-contained. To customize colors, speed, or size, use Grepped's workspace at grepped.dev/animations/state-feedback/glow.
Is the Glow free to use?
Yes. All Grepped preset animations are free to use in personal and commercial projects. You may copy, modify, and redistribute the code without attribution. The only limitation is that you may not resell the presets themselves as part of a competing animation library.
Does the Glow work on mobile browsers?
Yes. The Glow uses standard CSS animations and transforms that are supported in all modern mobile browsers — Chrome for Android, Safari on iOS 9+, Samsung Internet, and Firefox for Android. Where JavaScript is used for interactivity (e.g. cursor effects), it falls back gracefully on touch devices.
Can I customize the Glow's colors, speed, or size?
Yes. Open the live customization workspace at grepped.dev/animations/state-feedback/glow to adjust the animation with real-time sliders, color pickers, and toggles — no code required. For deeper changes, the source code uses CSS custom properties (variables) so you can edit them directly in your stylesheet.
Want to customize this animation or generate a new one from a text prompt?
Open in Workspace — it's free