> For the complete documentation index, see [llms.txt](https://docs.mapbox.com/help/llms.txt)

# font stack

A font stack is an ordered list of fonts that contains a primary font and an optional fallback font or fonts. In this example, `"Open Sans Regular"` is the primary font and `"Arial Unicode MS Regular"` is the fallback font:

```json
["Open Sans Regular", "Arial Unicode MS Regular"]
```

The font stack is defined within a map's symbol [layer](https://docs.mapbox.com/help/glossary/layer/). The font stack defines the order in which the renderer should try to find the characters used within the layer. If the renderer cannot find a character within the first font, then it will try to use the next one. It will repeat this process until it can find a font that has that character.

A [style object](https://docs.mapbox.com/api/maps/#the-style-object) itself does not have a main font stack. Rather, individual layers within the style object have their own font stacks that are defined within the [`text-font`](https://docs.mapbox.com/style-spec/reference/layers/#layout-symbol-text-font) property of a symbol layer, as detailed in the [Mapbox Style Specification](https://docs.mapbox.com/style-spec/).

**Related resources:**

-   Troubleshooting guide: [Manage your fontstacks](https://docs.mapbox.com/help/dive-deeper/manage-fontstacks/)
-   [Mapbox Studio symbol layer documentation](https://docs.mapbox.com/studio-manual/reference/styles/#symbol-layer)
-   [Mapbox GL JS `text-font` documentation](https://docs.mapbox.com/style-spec/reference/layers/#layout-symbol-text-font)