Free Animated Gradient CSS Online
Free Animated Gradient CSS Online is a free online tool by US AI. Animated backgrounds. It runs completely in your browser — no signup, no download, works on mobile and desktop.
📖 How to use
- Pick three colors, an angle and a speed to preview the animated gradient, then copy the CSS.
- Open the tool with the button above — it loads instantly.
- Your work stays on your device; nothing is uploaded anywhere.
✨ Why use this tool?
US AI's free animated gradient css online is fast, private and 100% free forever. Bookmark this page and share it with anyone who needs it.
❓ Frequently asked questions
How do animated CSS gradients work?
Animated gradients use CSS keyframes to slowly shift the background position of a large gradient, creating a smooth flowing color effect. The tool generates the gradient plus the keyframes animation code, so you just copy and paste it into your stylesheet.
Will the animation slow down my website?
No — the animation only moves the background position, which modern browsers handle on the GPU. It is lightweight and smooth on both desktop and mobile, with no JavaScript or video files involved.
How do I change the animation speed?
Pick your colors, then adjust the speed setting in the tool to preview the flow faster or slower. The copied CSS includes the animation duration, which you can also edit by hand later (for example from 8s to 15s).
Can I use animated gradients on mobile browsers?
Yes — CSS gradient animations work in all modern mobile browsers on Android and iPhone. The tool itself is fully responsive, so you can build and copy the code right from your phone.
How do I copy the keyframes CSS?
Choose three colors, an angle and a speed, preview the animation, then press the copy button. You get both the gradient background and the @keyframes block — paste them into your stylesheet and the animation starts immediately.
🎨 Need a static gradient? Try our Free CSS Gradient Generator tool.