Gantt chart maker

Type your plan, one task per line, and see it as a Gantt chart: bars on a calendar, grouped in sections, each starting when the tasks it waits for are done. It opens with a website redesign to change into your own project.

Write the plan

Double-click the chart to edit its plan beside a live preview. A task is its name, a colon, then when it starts and how long it takes:

Wireframes :2026-11-02, 4d starts on a date and takes four days (w for weeks, h for hours)
Build :build, after design, 2w waits for the task with the id "design"; "after a b" waits for both
Polish :3d starts when the task above it ends
Hand-over :until launch ends where another task starts
section Build starts a group of tasks, with its own colour

Progress and milestones

Tags before the dates mark a task: done fades its bar, active outlines it, crit turns it red for the critical path, and milestone draws a diamond instead of a bar, as does a length of 0d.

Working days

"excludes weekends" makes lengths count working days only, so a five-day task that starts on a Thursday ends the next Thursday. Add dates to skip public holidays too: excludes weekends, 2026-12-25. The calendar shades weekends when it shows single days.

Mermaid syntax

The plan is Mermaid's gantt syntax, so a chart from a README or a wiki pastes straight in, dateFormat and axisFormat included, and yours works there too. Lines that can't be read are listed under the editor with their line numbers, and the rest of the chart still draws.

Questions

Does the calendar change with the length of the plan?

Yes: a plan of a few weeks shows every day under its month, one of a few months shows weeks, and a longer one shows months under their year. "tickInterval 1week" or "axisFormat %d %b" choose for yourself.

Can I put a Gantt chart next to other diagrams?

It is one shape on the canvas, so notes, checklists and arrows can sit around it, and other charts or diagrams can share the page.

Is my plan uploaded?

No. It is saved in your browser with your other diagrams. Export it as PNG or SVG for a slide or a status report, or share it as a link.