The OnStart property is like the setup phase of an app. It runs once when the app opens and is used to prepare everything the app needs β like loading data, setting variables, or choosing the start screen.
Typical Uses:
- Load collections:
ClearCollect(Employees, '[dbo].[EmployeeTable]')
- Set global variables:
Set(CurrentUser, User())
- Navigate to a splash or login screen conditionally
- Preload data to improve performance
Bonus Tip:
Microsoft now recommends reducing the use of App.OnStart and moving logic to a screenβs OnVisible property to make apps more responsive. However, OnStart is still widely used for setting up app-level variables and initial configuration.


