For hobbyists, Lordicon and IconScout offer free tiers where you can download packs of animated UI icons. How to Download and Extract Your Items
Choose a destination on your computer. The file will end in .zip . Extract the Contents: Windows: Right-click the folder and select "Extract All..." macOS: Double-click the ZIP file to automatically unzip it. Download Animated Items zip
Open the folder to ensure the files are in the format you need (e.g., .json for web or .mov with transparency for video). Pro-Tips for Using Animated Assets For hobbyists, Lordicon and IconScout offer free tiers
Sites like Own3d or Nerd or Die offer ZIP packs containing animated alerts, overlays, and transitions. Download Animated Items zip