GanttPRO

GanttPRO is a dedicated online Gantt chart software that excels at visual project planning and scheduling. It's ideal for agency project managers who rely heavily on Gantt charts for client timelines, dependencies, and critical path analysis. Features include drag-and-drop scheduling, resource workload management, baseline comparison, and collaborative options like comments and file attachments. It can import/export from MS Project and Excel.

Pricing is per project manager, with team members free. It scores well for its specialization, providing a more powerful and user-friendly Gantt experience than the built-in charts found in most general PM tools.