The "declaration can be final" inspection only works in batch mode. This is presumably because that inspection used to be too expensive to carry out on thef ly. However, the current version of IDEA already calculates on the fly whether a class has subclasses and whether a method is overridden, in order to determine whether the override icon should be shown in the gutter. This part of the inspection could therefore be available on the fly with little extra cost. (I assume "Field can be final" is still too expensive to calculate on the fly.)