It can be crowded during weekends, holidays, and peak summer months; weekdays and off-peak seasons are generally less busy.
Paleis Het Loo can experience significant crowds, especially during weekends, Dutch national holidays, and the peak summer tourist season (June-August). The palace interior, in particular, can feel busy due to timed entry slots and relatively narrow passages. The gardens, though expansive, also see many visitors. To avoid the largest crowds, consider visiting on a weekday outside of school holidays, or during the shoulder seasons of spring and early autumn. Arriving early in the morning or later in the afternoon can also help to mitigate crowd levels.