Activities in a learning journey can be reordered by dragging them into the position you want in the builder. The order you set here decides how activities are listed visually, but each activity is still sent on its own schedule.
Drag to reorder
Open the learning journey in the builder, hover the activity you want to move, and drag it to the new position. The list updates as you drop.
Two orders to keep separate
Journey order is what participants see. It's the visual order of activities in the learning journey view, set in the builder by dragging.
Scheduling order is when activities arrive. Each activity has its own send date or schedule. A participant can see activity B above activity A in the learning journey list, but if A is scheduled earlier than B, A is what arrives first.
If you want activities to arrive in a specific order, set the schedule. If you want them to appear in a specific order in the learning journey view, drag them in the builder. They're independent — set both deliberately.
When reordering does and doesn't affect participants
Reordering activities that haven't been sent yet only changes the visual order in the builder and in the participant's learning journey view. Reordering activities that have already been sent has the same effect — the change is visual, not historical: participants who already received the activities don't get them again. Scheduled future activities still send on the date you set, regardless of where they sit in the list now.