GanttTool is a fully free, privacy-first Gantt chart generator designed for simple yet powerful project management. Built entirely in the browser, it stores all data locally through autosave, meaning no accounts, tracking, or server uploads are ever required. The platform leverages PlantUML to render elegant, professional diagrams that can be exported as SVG, PNG, or raw code for use in documentation. Users can define detailed tasks, dependencies, milestones, and project phases, with intelligent validation to prevent circular relationships. A flexible scheduling engine supports date-based timelines, offset-based planning, and dynamic dependency handling. Additional features include drag-and-drop task handling, custom colors and fonts, resource allocation indicators, and non-working days like weekends or holidays. Projects can be saved or loaded as JSON, allowing easy backup and sharing. Rated highly by project managers, GanttTool delivers advanced planning capabilities without cost or complexity.
