Loading State

Any time there's a wait, let the user know "the system is working, it hasn't frozen." Different cases call for different forms. When a whole block of content loads for the first time, use a Skeleton: gray blocks in the rough shape of the content. For partial refreshes or short waits, use a spinner. For long tasks where you can calculate progress (like uploads), use a progress bar. After a submit click, put the button itself into a loading state and block repeat clicks.

Requests that finish quickly (within 300ms) can skip the loading indicator so the UI doesn't flicker. Design the loading state separately from the empty state and the error state too. Still loading, no data, and something went wrong are three different screens.

When you ask AI for this, say which kind of loading indicator to use, where it goes, and which actions to disable while loading.