# Treemap

A React component in [Beamline](https://beamline.io/)'s [Charts & data-vis](https://beamline.io/components/charts) category. Live demo: https://beamline.io/components/treemap

Nested rectangles sized by value (spend by team, then service), squarified so tiles stay close to square: labels that fit or hide, hover and focus highlight, drill in with a click or Enter and out with Escape, Backspace or the breadcrumb, hatched chips for parts that were not measured, and a table of the current level.

## Use it for

- Part-to-whole over a hierarchy with drill-down: cloud spend by team and service, storage by folder, revenue by region and account.

## Not for

- Markets coloured by change ([market-heatmap](https://beamline.io/components/market-heatmap)).
- A few flat shares ([pie-chart](https://beamline.io/components/pie-chart)).
- Flows between stages ([sankey-chart](https://beamline.io/components/sankey-chart)).

## Anatomy

- title, description, breadcrumb (the way back up), table button
- tiles (buttons): the current level's children
- group header and nested tiles one level down (depth 2)
- tile label and value (shown only when they fit)
- readout (the hovered or focused tile's path, value and share)
- unmeasured chips (hatched) under the plot

## Variants

- **0**: depth: 1 (the current level only) · 2 (each tile shows its own children)
- **1**: level (controlled or not)

## States

- loading (skeleton)
- empty
- unmeasured parts (value null): left out of the area, listed as hatched chips that read “Not measured”
- hovered / focused tile (ring, others dim)
- drilled in (breadcrumb shows the path)
- a tile with unmeasured parts inside carries a small hatched mark; the readout counts them
- table view (the current level: value and share)
- right-to-left: tiles mirror (largest at the start edge)

## Keyboard

- Tab focuses one tile; arrow keys move to the nearest tile in that direction (mirrored in right-to-left)
- Enter or Space drills into a tile with children (or calls onSelect on a leaf)
- Escape or Backspace goes up one level and refocuses the tile you came from; at the top Escape is left to the page
- Breadcrumb items go straight to any level above

## Motion

Tiles fade in once; drilling zooms the new level out of the chosen tile (one motion-out); instant under reduced motion.

## Props

| Prop | Type | Default | Description |
| --- | --- | --- | --- |
| `data` | `TreemapNode` | — | The root: { key, label, value?: number \| null, children? }. A parent's value is the sum of its measured children. |
| `format` | `(value: number) => string` | — | How values read: "$42.0k". |
| `level / defaultLevel / onLevelChange` | `string` | — | Key of the node whose children fill the view. Default the root. |
| `depth` | `1 \| 2` | — | Levels shown at once. Default 2. |
| `height` | `number` | — | Plot height. Default 320. |
| `onSelect` | `(node: TreemapNode, path: TreemapNode[]) => void` | — | A leaf was chosen (click or Enter). |
| `title / hideTitle / description` | `string / boolean / ReactNode` | — | The figure's name (a heading unless hidden) is always its accessible name. |
| `table` | `boolean` | — | Offer “View as table”. Default true. |
| `loading` | `boolean` | — | Skeleton of the chart's shape; keeps the frame's size. |
| `actions` | `ReactNode` | — | Controls beside the legend (range, offset). |
| `className` | `string` | — | Lands on the figure. |
| `classNames` | `ChartClassNames` | — | Frame, tooltip and slice-list parts as applicable to this chart. |
| `style / ref` | `CSSProperties / Ref<HTMLElement>` | — | The native chart figure; layout measurement refs stay internal. |

## Dependencies

`motion`

## Import

```tsx
import { Treemap } from "@/components/treemap/treemap";
```

## Get it

Treemap is part of Beamline: 190 React components and screens your coding agent (Claude Code, Codex, Cursor or any MCP client) installs into your app through Beamline's MCP server, as a ready-built package or as plain React source you can change. $49 one payment (regular $200), no subscription, a year of updates, one licence for your whole team. [Get Beamline](https://beamline.io/checkout?pack=complete) · [Connect your agent](https://beamline.io/connect)

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