Gantt.

PRO

Arrange task durations and progress on a timeline.

Live preview36 feature examples

LIVE EXAMPLE

Project schedule

Match the page theme
Interact with the chart to see selection and range-change results here.
OptionsChanges are reflected in the preview and code.
Appearance and style6
Legend and interaction13
Title and dimensions3

Task durations, progress, and milestones. All values are sample data.

View code
Current preview
<div id="chart-container" style="width: 100%; min-width: 0;"></div>

<script type="module">
  import { defineCustomElement as define0 } from '@syidax/advanced-pro/components/sy-gantt-chart.js';
  define0();

  // Pro: complete registerLicense at app startup using your issued certificate.
  // The website preview certificate is not for use in customer apps.
  const specs = [
    {
      "id": "example-chart",
      "tag": "sy-gantt-chart",
      "props": {
        "data": [
          {
            "id": "research",
            "label": "Research",
            "start": "2026-01-05",
            "end": "2026-01-09",
            "progress": 1,
            "color": "#8263d9"
          },
          {
            "id": "design",
            "label": "Design",
            "start": "2026-01-08",
            "end": "2026-01-16",
            "progress": 0.65,
            "color": "#239c91"
          },
          {
            "id": "build",
            "label": "Implementation",
            "start": "2026-01-14",
            "end": "2026-01-26",
            "progress": 0.3,
            "color": "#e99954"
          },
          {
            "id": "launch",
            "label": "Release",
            "start": "2026-01-28",
            "milestone": true
          }
        ],
        "width": 640,
        "height": 360,
        "brandPosition": "bottom-right",
        "brandLogo": ""
      }
    }
  ];
  const container = document.querySelector('#chart-container');
  const elements = specs.map(({ tag, id, props }) => {
    const element = document.createElement(tag);
    element.id = id;
    Object.assign(element, props);
    element.setAttribute('aria-label', 'gantt example chart');
    return element;
  });
  container.replaceChildren(...elements);
  const chart = elements.at(-1);
  const onEvent = event => {
    console.log('taskClick', event.detail);
  };
  chart.addEventListener('taskClick', onEvent);
  const observer = new ResizeObserver(([entry]) => {
    const width = Math.max(160, Math.floor(entry.contentRect.width));
    elements.forEach(element => { element.width = width; });
  });
  observer.observe(container);

  // In an SPA, call this function when the view is disposed.
  function disposeChart() {
    observer.disconnect();
    chart.removeEventListener('taskClick', onEvent);
    container.replaceChildren();
  }
</script>

Usage and data

#

Manage project schedules, milestones, and baselines together.

This display example does not save tasks. Connect application persistence to editing events to save changes.

Data contract

PropertyInput format
dataAn array of tasks as { id, label, start, end?, progress?, milestone?, baseline? }. progress ranges from 0 to 1.

Updating data

Assign a new array or object to the property instead of mutating values inside an array. Chart events provide selection results through event.detail. When disposing of the view, clean up ResizeObserver and event listeners registered by your app.

Feature examples

#

Try 36 interactive feature examples and inspect their code. Select “Edit in preview” to combine more options in the settings panel above.

Show task progressPRO

Display the completion percentage inside each task bar.

Interact with the chart to see results here.
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Row spacingPRO

Compare schedules with reduced task heights and row spacing.

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Inspect values with the pointerPRO

Point to data to view the value at that location.

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Crosshair trackingPRO

Move the pointer to read horizontal and vertical coordinates alongside values.

Interact with the chart to see results here.
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Drag to zoom and panPRO

Drag to zoom and hold Shift to pan. Use Ctrl + wheel to zoom in or out.

Interact with the chart to see results here.
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Replay animationPRO

Redraw the same example to inspect its initial display animation.

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AccessibilityPRO

Compare 4 examples of Accessibility. Buttons and options update both the live result and source code.

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AnimationPRO

Compare 3 examples of Animation. Buttons and options update both the live result and source code.

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BaselinePRO

Compare 3 examples of Baseline. Buttons and options update both the live result and source code.

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ColorPRO

Compare 3 examples of Color. Buttons and options update both the live result and source code.

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Critical PathPRO

Compare 3 examples of Critical Path. Buttons and options update both the live result and source code.

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CrosshairPRO

Compare 3 examples of Crosshair. Buttons and options update both the live result and source code.

Interact with the chart to see results here.
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Data inputPRO

Compare 2 examples of Data input. Buttons and options update both the live result and source code.

Interact with the chart to see results here.
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DependenciesPRO

Compare 3 examples of Dependencies. Buttons and options update both the live result and source code.

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LabelPRO

Compare 3 examples of Label. Buttons and options update both the live result and source code.

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Large datasetsPRO

Compare 2 examples of Large datasets. Buttons and options update both the live result and source code.

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SizePRO

Compare 1 examples of Size. Buttons and options update both the live result and source code.

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Task barsPRO

Compare 4 examples of Task bars. Buttons and options update both the live result and source code.

Interact with the chart to see results here.
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Task EditingPRO

Compare 3 examples of Task Editing. Buttons and options update both the live result and source code.

Interact with the chart to see results here.
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Time AxisPRO

Compare 4 examples of Time Axis. Buttons and options update both the live result and source code.

Interact with the chart to see results here.
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TooltipPRO

Compare 14 examples of Tooltip. Buttons and options update both the live result and source code.

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Zoom and panPRO

Compare 3 examples of Zoom and pan. Buttons and options update both the live result and source code.

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Context menuPRO

Compare 1 examples of Context menu. Buttons and options update both the live result and source code.

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DependenciesPRO

Compare 1 examples of Dependencies. Buttons and options update both the live result and source code.

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HoverPRO

Compare 1 examples of Hover. Buttons and options update both the live result and source code.

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Data context menuPRO

Compare 1 examples of Data context menu. Buttons and options update both the live result and source code.

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RuntimePRO

Compare 1 examples of Runtime. Buttons and options update both the live result and source code.

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Selection ChangedPRO

Compare 1 examples of Selection Changed. Buttons and options update both the live result and source code.

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Task ClickPRO

Compare 1 examples of Task Click. Buttons and options update both the live result and source code.

Interact with the chart to see results here.
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Task EditPRO

Compare 1 examples of Task Edit. Buttons and options update both the live result and source code.

Interact with the chart to see results here.
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ExportPRO

Compare 1 examples of Export. Buttons and options update both the live result and source code.

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Read coordinates and dataPRO

Compare 2 examples of Read coordinates and data. Buttons and options update both the live result and source code.

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Runtime APIPRO

Compare 1 examples of Runtime API. Buttons and options update both the live result and source code.

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OptionalPRO

Compare 1 examples of Optional. Buttons and options update both the live result and source code.

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OverviewPRO

Compare 4 examples of Overview. Buttons and options update both the live result and source code.

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Streaming · Add and update live dataPRO

Compare 5 examples of Add and update live data. Buttons and options update both the live result and source code.

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API reference

#

The full public API for sy-gantt-chart. Pass objects and arrays as JavaScript properties. Select a name to view usage code and type definitions.

Key properties

Attribute / PropertyType / DefaultDescription
GanttDataDefault: undefinedAn array of tasks as { id, label, start, end?, progress?, milestone?, baseline? }. progress ranges from 0 to 1.
numberDefault: 900Chart width in pixels. Update with ResizeObserver when the container changes.
numberDefault: 400Chart height in pixels.
brandLogostringDefault: undefinedThe default is the Syidax logo. With the Pro chart.branding entitlement, use none or a PNG, JPEG, or WebP data URL.
brandPosition'top-left' | 'top-right' | 'bottom-left' | 'bottom-right'Default: 'bottom-right'The corner where the logo is anchored. Applies equally to Community and Pro, on screen and in image exports.
barHeightnumberDefault: 24Maximum task bar height and gap in CSS pixels.
rowGapnumberDefault: 4Set as an HTML attribute or JavaScript property. type: number.
barRadiusnumberDefault: 3Set as an HTML attribute or JavaScript property. type: number.
progressShowbooleanDefault: trueSet as an HTML attribute or JavaScript property. type: boolean.
progressColorstringDefault: 'auto'Set as an HTML attribute or JavaScript property. type: string.
CartesianCrosshairInputDefault: undefinedPass as a JavaScript property. type: CartesianCrosshairInput.
taskLabelsGanttLabelModeDefault: 'auto'Allowed values: auto, show, hide. Default: 'auto'.
chartTitlestringDefault: undefinedThe title inside the chart. Explain the data's unit and meaning alongside it.
chartSubtitlestringDefault: undefinedThe subtitle inside the chart.
CartesianTooltipInputDefault: undefinedTooltip settings for pointer-driven values, position, and content.
tooltipEnabledbooleanDefault: trueSet as an HTML attribute or JavaScript property. type: boolean.
animatedbooleanDefault: falseWhether to animate initial display and data changes.
animationDurationnumberDefault: 600Animation duration in milliseconds.
animationEasingGanttEasingDefault: 'ease-out'Allowed values: linear, ease-out, ease-in, ease-in-out. Default: 'ease-out'.
animationTypeGanttAnimationTypeDefault: undefinedAllowed values: initial, update. Default: undefined.
CartesianZoomInputDefault: undefinedSettings for zooming and the visible range.
Other properties 18
Attribute / PropertyType / DefaultDescription
taskLabelFormat(task:GanttTask)=>stringDefault: undefinedPass as a JavaScript property. type: (task:GanttTask)=>string.
timeDomainreadonly [number, number]Default: undefinedOptional full timeline extent in epoch milliseconds.
criticalPathGanttCriticalPathInputDefault: undefinedPass as a JavaScript property. type: GanttCriticalPathInput.
taskEditingGanttTaskEditingInputDefault: undefinedOpt-in task move/resize. Committed local edits are queried through getTasks/getTaskEdits; source updates supersede them.
GanttBaselineStyleInputDefault: undefinedReference-date strips, visible by default when tasks include baseline dates.
ReadonlyArray<GanttDependencyInput>Default: undefinedPass as a JavaScript property. type: ReadonlyArray<GanttDependencyInput>.
dependencyStyleGanttDependencyStyleInputDefault: undefinedPass as a JavaScript property. type: GanttDependencyStyleInput.
timeAxisGanttTimeAxisInputDefault: undefinedPass as a JavaScript property. type: GanttTimeAxisInput.
crosshairTimeUnitGanttCrosshairTimeUnitDefault: 'hour'Crosshair time badge precision; hour by default. Uses timeAxis.utc without changing event timestamps.
stringDefault: 'auto'Set as an HTML attribute or JavaScript property. type: string.
activeColorstringDefault: '#f59e0b'Set as an HTML attribute or JavaScript property. type: string.
enableMouseTrackingbooleanDefault: trueSet as an HTML attribute or JavaScript property. type: boolean.
tooltipFormat(detail: GanttHitDetail) => stringDefault: undefinedPass as a JavaScript property. type: (detail: GanttHitDetail) => string.
streamSourceGanttStreamSourceDefault: undefinedA stream source for live data. Check the contract for the specific type.
streamMaxnumberDefault: undefinedThe maximum number of streaming data points to retain.
streamWindownumberDefault: undefinedThe streaming data range to keep visible.
GanttEngineModeDefault: 'auto'Renderer selection: auto, standard, or pro. Engine selection is separate from permission to use a Pro chart type.
GanttUnavailableBehaviourDefault: 'fallback'Allowed values: fallback, error. Default: 'fallback'.
Events 22
EventsDetail typeDescription
GanttRenderResult & { tier: GanttEngineTier }Emits rendering results in detail when chart drawing completes.
GanttDependencyHitDetailCustomEvent.detail type: GanttDependencyHitDetail. Event names are case-sensitive.
GanttDependencyHitDetail | nullCustomEvent.detail type: GanttDependencyHitDetail | null. Event names are case-sensitive.
GanttDependencySelectionChangeCustomEvent.detail type: GanttDependencySelectionChange. Event names are case-sensitive.
GanttHitDetailCustomEvent.detail type: GanttHitDetail. Event names are case-sensitive.
GanttHitDetail | nullCustomEvent.detail type: GanttHitDetail | null. Event names are case-sensitive.
GanttTaskEditEventDetailCustomEvent.detail type: GanttTaskEditEventDetail. Event names are case-sensitive.
GanttTaskEditEventDetailCustomEvent.detail type: GanttTaskEditEventDetail. Event names are case-sensitive.
GanttTaskEditEventDetailCancelable before local dates, completion and row order commit. preventDefault restores the prior state.
GanttTaskEditEventDetailCustomEvent.detail type: GanttTaskEditEventDetail. Event names are case-sensitive.
GanttSelectionChangeEventDetailCustomEvent.detail type: GanttSelectionChangeEventDetail. Event names are case-sensitive.
ChartPointContextMenuEventDetail<GanttHitDetail>CustomEvent.detail type: ChartPointContextMenuEventDetail<GanttHitDetail>. Event names are case-sensitive.
{ count: number; replaced: number }CustomEvent.detail type: { count: number; replaced: number }. Event names are case-sensitive.
{ dropped: number }CustomEvent.detail type: { dropped: number }. Event names are case-sensitive.
CartesianTooltipEventDetailWhether to display the built-in tooltip.
voidCustomEvent.detail type: void. Event names are case-sensitive.
CartesianTooltipActionEventDetailCustomEvent.detail type: CartesianTooltipActionEventDetail. Event names are case-sensitive.
voidCustomEvent.detail type: void. Event names are case-sensitive.
voidCustomEvent.detail type: void. Event names are case-sensitive.
voidCustomEvent.detail type: void. Event names are case-sensitive.
CartesianZoomChangeEventDetailCustomEvent.detail type: CartesianZoomChangeEventDetail. Event names are case-sensitive.
CartesianCrosshairEventDetail | nullCustomEvent.detail type: CartesianCrosshairEventDetail | null. Event names are case-sensitive.
Methods 50

Stencil methods return Promises. Use await within an async function to read the result.

Method / ArgumentsReturn typeDescription
Promise<GanttCriticalPathResult>An asynchronous method. Check the argument and return types below.
Promise<GanttDependencyDataset>An asynchronous method. Check the argument and return types below.
Promise<GanttDependencyPath[]>An asynchronous method. Check the argument and return types below.
cssX: number, cssY: numberPromise<GanttDependencyHitDetail|null>An asynchronous method. Check the argument and return types below.
Promise<GanttDependencySelection>An asynchronous method. Check the argument and return types below.
index: numberPromise<GanttDependencyHitDetail|null>An asynchronous method. Check the argument and return types below.
index: numberPromise<CartesianTooltipEventDetail|null>An asynchronous method. Check the argument and return types below.
Promise<GanttRenderResult>An asynchronous method. Check the argument and return types below.
Promise<ChartEngineStatus>Requested engine vs what runs, and why (CHART-ADD-08); a frozen or unlicensed chart reports the license outcome.
Promise<GanttEngineTier>An asynchronous method. Check the argument and return types below.
Promise<string | undefined>An asynchronous method. Check the argument and return types below.
data: GanttDataPromise<void>An asynchronous method. Check the argument and return types below.
Promise<GanttTask[]>An asynchronous method. Check the argument and return types below.
index: numberPromise<GanttTask | null>An asynchronous method. Check the argument and return types below.
id: stringPromise<GanttTask | null>An asynchronous method. Check the argument and return types below.
Promise<GanttDiagnostics>Normalization diagnostics for the effective base and stream source.
Promise<number>An asynchronous method. Check the argument and return types below.
Promise<GanttExtent>An asynchronous method. Check the argument and return types below.
Promise<GanttLayoutResult>An asynchronous method. Check the argument and return types below.
Promise<GanttBaselineComparison[]>Reference comparisons for every accepted task, including hidden/offscreen baselines. Positive variance means later or longer.
task: GanttTaskInputPromise<void>An asynchronous method. Check the argument and return types below.
tasks: ReadonlyArray<GanttTaskInput>Promise<void>An asynchronous method. Check the argument and return types below.
count: numberPromise<void>An asynchronous method. Check the argument and return types below.
tasks: ReadonlyArray<GanttTaskInput>Promise<void>An asynchronous method. Check the argument and return types below.
Promise<GanttStreamSource | undefined>An asynchronous method. Check the argument and return types below.
Promise<void>An asynchronous method. Check the argument and return types below.
Promise<void>An asynchronous method. Check the argument and return types below.
Promise<void>An asynchronous method. Check the argument and return types below.
options: { enabled?: boolean; duration?: number; easing?: GanttEasing; type?: GanttAnimationType }Promise<void>An asynchronous method. Check the argument and return types below.
cssX: number, cssY: numberPromise<GanttHitDetail | null>An asynchronous method. Check the argument and return types below.
index: numberPromise<GanttHitDetail | null>An asynchronous method. Check the argument and return types below.
Promise<void>An asynchronous method. Check the argument and return types below.
Promise<GanttSelection>An asynchronous method. Check the argument and return types below.
index: numberPromise<CartesianTooltipEventDetail | null>An asynchronous method. Check the argument and return types below.
index: numberPromise<CartesianTooltipEventDetail | null>An asynchronous method. Check the argument and return types below.
Promise<void>An asynchronous method. Check the argument and return types below.
Promise<GanttTaskEdit[]>Committed local dates, completion and displaced rows; never mutates caller data.
id?: stringPromise<void>An asynchronous method. Check the argument and return types below.
Promise<boolean>An asynchronous method. Check the argument and return types below.
request: CartesianZoomRequestPromise<CartesianZoomChangeEventDetail | null>Zoom to an explicit millisecond x window. Task rows do not accept y zoom requests.
factor: number, anchorFraction?: numberPromise<CartesianZoomChangeEventDetail | null>Scale the current windows by `factor` (< 1 zooms in) around `anchorFraction` (0..1, default centre).
delta: { x?: number; y?: number }Promise<CartesianZoomChangeEventDetail | null>Slide the zoomed windows by milliseconds (`{ x?, y? }`); a no-op at the full extent.
Promise<CartesianZoomChangeEventDetail | null>Back to the full diagram.
Promise<CartesianZoomState | null>The current zoom state (`null` = the full diagram).
request?: CartesianZoomExtentRequestPromise<CartesianZoomExtentDetail | null>The full timestamp extent and axis key (`null` before the first layout).
Promise<ChartDataTable>An asynchronous method. Check the argument and return types below.
Promise<GanttLabel[]>An asynchronous method. Check the argument and return types below.
Promise<GanttTimeAxisModel>An asynchronous method. Check the argument and return types below.
request: CartesianCrosshairShowRequestPromise<boolean>Quiet sync API: epoch milliseconds and a zero-based task row; no crosshairMove feedback loop.
Promise<void>An asynchronous method. Check the argument and return types below.