> For the complete documentation index, see [llms.txt](https://developers.felt.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.felt.com/felt-style-language/types-of-visualizations/heatmaps.md).

# Heatmaps

Heatmaps are used to visualize the density of points on a map.

Heatmaps work on point layers only, and show concentration rather than individual feature values — if you need to read a specific attribute, use a [numeric](/felt-style-language/types-of-visualizations/numeric-visualizations-color-and-size.md) visualization instead. The `config` block must be empty (`{}`), and heatmaps support no popups or labels.

Heatmaps visualizations are defined using `“type”: “heatmap”` and allow the following properties to be set:

| Field name  | Type   | Default     | Typical range | Description                                                                                                        |
| ----------- | ------ | ----------- | ------------- | ------------------------------------------------------------------------------------------------------------------ |
| `color`     | string | `"@geyser"` | —             | A [heatmap palette](/felt-style-language/colors-and-palettes.md#heatmap-palettes) name, from less density to more. |
| `size`      | number | 10          | 1–30 px       | Radius of influence in pixels. Larger = smoother, smaller = more detailed.                                         |
| `intensity` | number | 0.5         | 0.1–3.0       | How quickly density saturates. Higher = more contrast.                                                             |
| `opacity`   | number | 0.9         | 0–1           | Transparency.                                                                                                      |

Tune `size` for the zoom you expect to view at — larger at low zoom, smaller at high zoom.

This is an example of a heatmap visualization

![](/files/C2vt8DBqzgRiZC3rorOO)

defined with the following visualization

```jsx
{
  "version": "2.3.1",
  "type": "heatmap",
  "config": {},
  "legend": {"displayName": {"0": "Low", "1": "High"}},
  "paint": {"color": "@purpYlPink", "size": 10, "intensity": 0.2}
}
```

Heatmaps do not support labels.


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