GanttTool is a completely free, browser-based project management tool that lets users create professional Gantt charts without limits or signups. It uses PlantUML to generate clean, customizable diagrams, allowing teams to plan and visualize projects in just minutes. All data stays locally in the user’s browser, ensuring full privacy with no tracking or server storage. The tool supports tasks, milestones, dependencies, scheduling offsets, and project phases with smart cycle detection. Users can export charts as SVG or PNG or retrieve the full PlantUML code for flexibility. With features like auto-save, drag-and-drop reordering, resource tracking, and custom styling, GanttTool makes project visualization simple and accessible.