How to Use Online Gantt Chart Maker: Step-by-Step Guide
Reviewed by the OnlineFree.app team · Updated
Key points
- Online Gantt Chart Maker needs one task per line: name, start date, end date, then optional progress from 0 to 100.
- It accepts YYYY-MM-DD or MM/DD/YYYY, and ISO dates avoid the ambiguity of formats like 03/04/2025.
- Dependencies are typed as prerequisite -> dependent and drawn finish-to-start between the matching bars.
- PNG exports render at 2x device pixel ratio; CSV includes a Duration (days) column; ICS creates all-day calendar events.
- The tool has no backend, so your pasted tasks disappear on refresh — export before closing the tab.
How to use Online Gantt Chart Maker step by step
The whole job takes three moves: paste one task per line with a start and end date, optionally add dependency arrows, then pick PNG, CSV or ICS and download. The chart redraws as you type, so there is no Generate button, no signup screen and nothing to install.
Open Online Gantt Chart Maker and paste a block like "Design mockups, 2025-01-06, 2025-01-10" on the first line, "Frontend build, 2025-01-11, 2025-01-20" on the second and "QA pass, 2025-01-21, 2025-01-24" on the third. Within a keystroke or two you get a date-scale header with day and week columns, month labels, one bar per task, and a vertical today marker so you can see how far along the schedule you are.
If the preview looks wrong, the fix is almost always in the input text, not in a setting. Read the flagged lines, correct the dates, and the bars snap into place immediately.
Format your task list so it parses first time
Each line follows a fixed order: task name, start date, end date, and an optional progress number from 0 to 100. Commas, tabs and pipe characters all work as separators, so you can copy a block out of a spreadsheet, a notes app or a chat message without reformatting it.
Blank lines are skipped, which means you can leave visual gaps between phases of work. A line only fails when it does not resolve to a valid date pair, and the tool flags those instead of guessing what you meant.
One practical trap: if you use commas as the separator, keep commas out of task names. "Design mockups, round 2, 2025-01-06, 2025-01-10" gives the parser four fields where it expects three. Switch that block to tabs or pipes, or rename the task, and it will read correctly. The progress value is optional, so a plain three-field line renders a solid bar with no fill overlay.
Which date formats does the Gantt chart accept?
Two formats resolve: ISO-style YYYY-MM-DD and US-style MM/DD/YYYY. ISO is the safer choice, because 03/04/2025 reads as March 4 in one office and April 3 in another, and the tool has to commit to one interpretation when it draws the bar.
Date ranges are counted inclusively in the CSV export. A task running from 2025-01-06 to 2025-01-10 appears in the Duration (days) column as 5, because both the start and the end day count. That matches how most people describe a working week, but check it against your own contract wording if you bill by the day.
The scale adapts to your span. A two-week project shows day columns and week labels; a six-month project compresses into a readable strip without you changing anything. Nothing is estimated for you — every bar reflects the dates you typed, so a wrong date is a wrong bar.
How dependencies work on the timeline
Dependencies live in their own box, one arrow per line, written as prerequisite -> dependent. In the sample above you would type "Design mockups -> Frontend build" and "Frontend build -> QA pass" to link the three phases.
Arrows are drawn finish-to-start: the line starts at the end of the earlier bar and points at the start of the later one, which is the convention used in most project charts described on Wikipedia's Gantt chart page. The name on each side of the arrow has to match a task in the list above, so keep spelling and spacing identical. A typo does not create a new task — it simply produces no arrow, which is easy to miss if you only glance at the preview.
The tool draws the links you declare; it does not reschedule anything. If a prerequisite slips from January 10 to January 14, the dependent bar stays where you put it until you edit that date yourself.
Exporting as PNG, CSV or ICS
PNG is the shareable artifact. It renders at 2x device pixel ratio through the browser canvas, so text stays crisp on high-DPI screens and in slide decks, and the file arrives named gantt-chart-YYYY-MM-DD.png with a title and a generated-on date in the footer. That footer date is worth keeping, since it tells a reader which version of the plan they are looking at.
CSV is the round-trip format. Columns are Task, Start, End, Duration (days), Progress % and Depends On, written with a UTF-8 byte-order mark so Excel opens accented characters cleanly instead of scrambling them. Re-importing the file into Google Sheets or Excel gives you a sortable, filterable version of the same schedule.
ICS is for calendars. Each task becomes one all-day VEVENT, and the end date is adjusted to the exclusive day required by RFC 5545, so a task ending 2025-01-10 imports into Google Calendar or Apple Calendar as an event that still includes January 10. Long tasks appear as day-long blocks, not as timed meetings, which is exactly what you want for milestones.
Limits to keep in mind before you share it
There is no backend and no account, which is good for privacy and bad for persistence. Close the tab or refresh the page and the pasted list is gone, because nothing is stored on a server or in a login. Export the PNG, CSV or ICS before you navigate away, every time.
This is a timeline drawing tool, not a scheduling engine. It does not level resources, calculate a critical path, or warn you that two people are double-booked. You supply the sequence and the dates; it supplies the picture. For a five-to-fifty-task plan that is usually the right trade.
Two habits keep the output trustworthy. First, cross-check the Duration (days) figure in the CSV against your own day-count assumptions. Second, send the PNG alongside the ICS file, because a picture answers "what does the plan look like" and a calendar file answers "when do I need to be done." If your plan is really a knockout schedule rather than a calendar, the Tournament Bracket Maker is the better fit, and the rest of the OnlineFree.app free online tools collection covers the same no-signup pattern.
Frequently asked questions
Is Online Gantt Chart Maker free and account-free?
Yes. Online Gantt Chart Maker runs entirely in your browser with no signup, no login and no backend storage. You paste tasks, see the chart render, and export it as PNG, CSV or ICS at no cost. Because nothing is saved server-side, refreshing or closing the tab clears your task list, so download an export before you leave the page.
Can I open the exported file in Excel or Google Sheets?
Yes, choose CSV as the export format. The file contains the columns Task, Start, End, Duration (days), Progress % and Depends On, and it is written with a UTF-8 byte-order mark so Excel opens accented task names correctly. You can re-sort or filter the rows in Sheets, though editing them there will not change the chart in Online Gantt Chart Maker.
How do I add dependencies between tasks in Online Gantt Chart Maker?
Put one arrow per line in the Dependencies box, written as prerequisite -> dependent, for example "Design mockups -> Frontend build". Arrows are drawn finish-to-start between the two bars. Each name must match a task in the list above exactly, including spelling and spacing, or no arrow appears and the link is silently skipped.
Why does a task not show up on the Gantt chart?
A missing bar usually means the line did not resolve to a valid date pair, so the tool flagged it instead of guessing. Check that the line has a task name followed by two dates, and that you have not mixed separators or left a comma inside the task name. Blank lines are skipped by design, so empty rows never cause errors.
Can I import the schedule into Google Calendar?
Yes, export as ICS and import the file into Google Calendar or Apple Calendar. Each task becomes one all-day VEVENT, and the end date is adjusted to the exclusive day required by RFC 5545, so a task ending 2025-01-10 still covers January 10 in your calendar. Progress percentages are not carried over into the calendar events.