Diagramium review
A capable free Gantt editor for visual planning, presentations, and exports.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Diagramium is a browser-based Gantt chart editor for developers, product managers, teachers, analysts, support teams, and other project planners. It covers core schedule visualization with task bars, start dates, durations, dependency arrows, zero-duration milestones, percent-complete indicators, and a Today marker. Daily, weekly, and monthly timeline scales support different planning horizons, while project-day schedules and calendar dates add flexibility for organizing work.
Pricing is straightforward: the Guest plan costs $0 per month and requires no account. It includes all 27 diagram types, PNG and PDF exports, and charts saved in the browser and user files. A free account also costs $0 per month and adds animated GIF, video, and animated SVG exports, along with all themes and Studio features. Subscription plans are not available yet. This makes Diagramium a practical choice for individuals or teams that need visual Gantt planning without a paid tier, especially when presentation and export options matter.
The standout capability is its combination of dependency mapping and critical-path highlighting, supported by progress indicators and multiple timeline scales. Step-by-step presentation with optional narration can turn a schedule into a guided walkthrough. The trade-off is a narrow planning focus: the published feature set does not include resource management, workload views, or integrations. Charts are local-first, stored in the browser rather than cloud-synced, although the editor works offline after loading. Choose Diagramium for free, visual project schedules and exported presentations; choose another tool if shared online workspaces, resource planning, workload analysis, or integrations are central requirements.
Diagramium pros and cons
- Where it wins
- Dependencies, milestones, progress indicators, and critical-path highlighting
- Free guest access with PNG and PDF exports
- Presentation mode plus PNG, PDF, SVG, and animated exports
- Where it doesn't
- No resource management or workload views
- No integrations with other platforms
- Charts are stored locally rather than cloud-synced
Diagramium fact sheet, pricing and score →
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