How long should a loading animation be?
10 seconds is about the limit for keeping the user's attention focused on the dialogue. For the longer delays, users perform other tasks while waiting for the device to load, so they should be given feedback displaying the expected time to complete.
How long should a preloader last?
A preloader animation can decrease the bounce rate
The current attention span is around 8 seconds, and that has tremendous implications for those designing digital content.