Gantt Chart Generator

What this tool does

Two things make project planning painful: overlapping tasks that are hard to spot, and redrawing the whole chart after a single date change. This generator takes a task name, start date, end date and progress value per row, then lays them out on a timeline where bar length is duration and an inner fill shows how much is done. Milestones get their own diamond marker.

Dependencies can be set between tasks, and the arrows run from predecessor to successor; move a predecessor's end date and the later bar follows. The timeline range is derived from the earliest start and latest finish across all rows, and a zoom slider lets you inspect a crowded fortnight or pull back to see the whole project.

Export comes as PNG or SVG. PNG drops straight into a weekly report, while SVG stays sharp when scaled inside a document. The canvas resolution follows its container, so narrow screens do not stretch the labels out of shape.

The timeline is derived from the earliest start and the latest end across all rows, which means adding a task that begins earlier or finishes later automatically widens the axis rather than clipping the bar. Each bar's length is the number of days between its start and end, and the inner fill is the progress percentage you supplied; the tool does not infer progress from dates, so a task can be shown as half complete even if its end date is still weeks away. Dependency arrows are drawn from the predecessor's finish to the successor's start. They express order, not automatic rescheduling: if you move a predecessor past its successor, both bars still appear where their dates say, and it is up to you to notice the overlap. A milestone is simply a zero-duration task rendered as a diamond, which is a compact way to mark a review, a freeze or a launch without inventing a separate data type. The zoom slider changes how much horizontal space a day occupies without changing the underlying dates, so it is presentational rather than a different schedule. PNG export produces a bitmap at the current canvas resolution for pasting into a report; SVG keeps the bars, labels and connectors as vectors for documents that may be scaled. Both are snapshots of the state at export time, so edit the rows and export again when the plan changes. Date parsing expects one consistent format, and a row with a different one is named in the message rather than dropped without warning.

Key features

• Row-by-row entry: Name, start, end and progress are entered per row; adding or removing a task redraws the axis immediately.
• Dependency arrows: Choose a predecessor to draw a connector; changing the earlier date shifts the dependent bar.
• Milestone markers: Zero-duration tasks render as diamonds, which suits reviews and launch dates.
• Progress fill: Each bar is filled in proportion to completion, making slippage visible at a glance.
• Zoom and two exports: A slider controls timeline density, and results export as PNG or SVG.
• Responsive canvas: Preview resolution is set from the container width so resizing never distorts the chart.

How to use it

1. List tasks: Fill name, start date, end date and progress for each row, adding rows as needed.
2. Mark dependencies: Pick a predecessor for tasks that must follow another; connectors appear in the chart.
3. Add milestones: Write reviews or launches as same-day tasks and tick the milestone option.
4. Press Generate: The right side draws the axis, bars, progress fill and dependency lines.
5. Export the chart: Choose PNG or SVG depending on whether it goes into a report or a document.

Things to keep in mind

• One date format: Use the prompted YYYY-MM-DD form; a row with a different format is skipped and called out.
• End cannot precede start: Backwards dates cannot be drawn, and the tool points to the exact row.
• Arrows do not reschedule: Dependencies show order only; conflicting successors are not pushed later automatically.
• Progress is display only: Percentages are entered by you; the tool does not connect to a task system or infer completion.
• Exports are snapshots: PNG and SVG capture the chart at that moment, so export again after editing tasks.