In GanttPRO Gantt diagram maker, you can change a task type after adding it. In particular, it is possible to:
- Choose Indent or Outdent option
- Convert a task to a milestone and vice versa
- Use drag&drop to change task type
Indent and Outdent
Click on the three-dots button on the right side of the task name 1 and select Indent 2. This will convert a task into a subtask of a previous one. The task you indent will go down one level in the WBS hierarchy.
In this example, we have applied Indent to a Subtask 3. As a result, it has been converted into a subtask to a Subtask 2.
Subtask 2 has become a summary task.
For the reverse process, to convert a subtask into a task, click on the three-dots button on the right side of the task name 1 and select Outdent 2. The task you outdent will go up one level in the WBS hierarchy.
In this example, we have applied Outdent to a Subtask 1, and as a result, it has been converted into a task and has gone up one level in the WBS hierarchy.

Convert a task to a milestone
Click on the three-dots button 1 on the right side of the task name and select Convert to milestone 2.
To revert a milestone into a task, select Convert to task. You can also change a task into a milestone through the Task settings.
Drag and drop tasks
Change task type by dragging it on the project grid and dropping it where needed. Depending on the placement, you can convert a task into a summary task or subtask, or simply adjust its order in the WBS.