Computer-implemented methods, media, and systems implemented to handling timer-based resizing events based on activity detection can trigger a start of a resize timer. The resize timer can periodically provide a notification to check for resize activity in a user interface displayed on a display device. In response to the notification, an absence of the resize activity can be determined after a threshold inactivity time period has expired from the start of the resize timer. In response, a stop of the resize timer can be triggered. After triggering the stop, a first resize activity associated with a first timestamp can be detected in the user interface. A restart of the resize timer from the first timestamp can be triggered to periodically provide the notification to check for resize activity in the user interface. Subsequent continuation or stopping of the resize timer can be based on further presence or absence of resize activity.