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Free Gantt Chart Generator Online – Dependencies, Critical Path & Excel Formulas

Create a professional Gantt chart with dependencies, critical path, milestones and live Excel formulas. Free, private and entirely in your browser — export to Excel, PDF, PNG, MS Project XML and more.

By DocSample · 23 October 2026 · 5 min read

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Free Gantt Chart Generator Online – Dependencies, Critical Path & Excel Formulas

A clear project timeline helps everyone see what happens when, which tasks depend on others, and which ones sit on the critical path. Most free online Gantt tools either limit features, require an account, or store your plan on a server. DocSample’s Free Gantt Chart Generator works differently: you build the full schedule in the browser, see the chart update live, and download it in multiple formats — including an Excel file that keeps working formulas.

What the Free Gantt Chart Generator Does

The Free Gantt Chart Generator turns a simple task list into a professional timeline. You can:

  • Add tasks with names, owners, start dates, durations and percentage complete
  • Group tasks into phases with automatic WBS numbering
  • Mark milestones
  • Define dependencies (finish-to-start, start-to-start, finish-to-finish) with lag
  • See the critical path, float, late tasks and today’s date highlighted on a live chart
  • Skip weekends and add your own holidays
  • Choose working days or calendar days for durations
  • Export to Excel (.xlsx) with live formulas, PDF, PNG, SVG, Word (.docx), CSV, Microsoft Project XML or JSON

Everything runs in the browser. No sign-up, no upload, and closing the tab clears the data.

Step-by-Step: How to Build a Gantt Chart

  1. Open the Gantt Chart Generator and choose a ready-made template (software, construction, marketing, event or thesis) or start blank.
  2. Enter project details: name, manager, start date, status date, whether durations are working days or calendar days, weekend settings, and any holidays.
  3. Add tasks. Type the name, owner, start date and duration (or end date). Indent rows to group them under phases; the tool assigns WBS numbers automatically.
  4. Set dependencies in the Predecessors column using row numbers and link types. Examples: `3` (finish-to-start from row 3), `3FS+2` (finish-to-start with 2 days lag), `4SS` (start-to-start), `5FF` (finish-to-finish).
  5. Update % done as work progresses. The chart refreshes immediately.
  6. Review the live view. Critical-path tasks appear highlighted, float is shown, late tasks are flagged, and today’s date is marked.
  7. Download the result in the format you need.

The schedule recalculates in real time whenever you change a date, duration or dependency.

Dependencies, Critical Path and Float

Dependencies control the sequence. Finish-to-start is the most common (one task must finish before the next starts). Start-to-start and finish-to-finish are also supported, with optional lag.

The critical path is calculated with the standard Critical Path Method:
- Forward pass finds the earliest start and finish dates from the dependencies.
- Backward pass finds the latest dates from the project finish.
- Tasks with zero total float are critical. Any delay on those tasks pushes the project end date.

The live chart highlights critical tasks (usually in red) and shows float so you can see which activities have slack.

Export Options and What You Get

  • Excel (.xlsx) – Contains live formulas (WORKDAY or WORKDAY.INTL for dates, NETWORKDAYS, SUMPRODUCT for weighted progress, conditional formatting for the timeline bars). Linked start dates use MAX of predecessor results. Compatible with Excel, Google Sheets and LibreOffice. Critical path and float values are written as numbers; re-export after major changes to update them.
  • PDF – Print-ready on A4, Letter or A3. Large plans can be split across pages.
  • PNG and SVG – Image versions of the chart for presentations or documents.
  • Word (.docx) – A document export of the plan.
  • CSV – Simple spreadsheet data.
  • Microsoft Project XML – Includes tasks, durations, dependencies, lag, % complete, owners, holidays and outline levels so you can open it in MS Project or ProjectLibre.
  • JSON – An editable copy of the whole plan. Save it and reopen later to continue editing.

Practical Tips

  • Prefer working days when you plan to use the Excel export. This keeps the browser calculation aligned with Excel’s WORKDAY and NETWORKDAYS functions.
  • Save a JSON copy regularly as a backup you can reopen.
  • Use A3 PDF for larger plans so the timeline remains readable.
  • After significant schedule changes, re-export the Excel file if you need the latest critical-path and float numbers.
  • Dates are whole days only; the tool does not schedule by the hour.

Privacy and Limitations

All processing stays in the browser. Plans are held only in local storage and disappear when you close the tab. There is no account and nothing is sent to a server.

A few practical limits apply: dependencies are limited to FS, SS and FF; links on phase rows are ignored; the Excel timeline uses a fixed number of columns; and PDF uses a standard font (some non-Latin characters may not render). These constraints keep the tool fast and reliable for most project plans.

Frequently Asked Questions

Does the Excel file really contain formulas?
Yes. End dates, linked starts, phase summaries and progress use Excel formulas that recalculate when you change inputs.

Can I open the Excel file in Google Sheets?
Yes. Upload the .xlsx to Google Drive and open it in Sheets; the formulas and formatting are supported.

How is the critical path calculated?
By the standard forward and backward passes. Tasks with zero total float are critical.

Can I import into Microsoft Project?
Yes, via the MS Project XML export.

Is it free and private?
Yes. No sign-up, no upload, and all work happens in the browser.

Final Takeaway

A useful Gantt chart shows not only when tasks happen but how they depend on each other and which ones control the finish date. The Free Gantt Chart Generator lets you build that view quickly, watch it update live, and export a formula-driven Excel file, a print-ready PDF, images, or an MS Project file — all without an account or uploading your plan. Start with a template or a blank list, set the dependencies, and download the result you need.

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Tags: Gantt chart generator, free Gantt chart, project timeline, critical path method, Gantt chart Excel formulas, project dependencies, milestone chart, WBS Gantt, free project planner, DocSample, client-side Gantt

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