---
title: "Editing JSON | Guides | Map design"
description: "Edit map styles and expressions using the JSON editor."
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Editing JSON

This page explains how to edit JSON in MapTiler Map Designer. The **JSON editor** in **MapTiler Map Designer** allows the writing or adjustment of any **style.json code**. Cartographers and other advanced users can leverage this to **manipulate complex data expressions** that are not editable on the UI.

## JSON editor

JSON editor can be accessed after **clicking on a specific layer**. Either navigate to the bottom of the page and click the **{ } symbol** or use the **Alt+E shortcut**.

![json-editor.png](./17141988221969_5a5fd2ca82.webp)

After opening the JSON editor, you will see the JSON syntax of the selected layer. You can directly type or paste into the editor, and in case of a **syntax error**, you will be notified with **code marked in red**. After hovering a mouse over it, you will get suggestions for fixes. MapTiler Map Designer is compliant with [GL Style Specification](https://docs.maptiler.com/gl-style-specification/). 

![json-error.png](./17141979335569_c3c484909e.webp)

## Search functions

When working with complex JSON layers, the search functions might come in handy. You can use the **search dialogue** directly in the JSON editor to look for specific text sequences or use **focus functionality**.

With the **search**, it is possible to use **find & replace** based on match case, whole words, or regular expressions. Search is available through the magnifier icon.

![json-search.png](./17141988226065_fe30de6a5a.webp)

With the **focus**, you can have only specific JSON properties visible in the editor: layout, paint, metadata, or filter. Focus is a drop-down menu atop the JSON field.

![json-focus.png](./17141979347089_0f094aaff8.webp)

## Fallback on complex expressions

MapTiler Map Designer UI currently **does not support the editing of complex data expressions** (such as  “match”, “case” or “get”) or **nested** ones. If such an expression is used in a map style, Map Designer will let you know by the **“Set by expression”** button that will switch to JSON editor with a click. There, it is possible to edit or write any expression compliant with JSON syntax.

![json-expression.png](./17141988230673_edb75ebbc6.webp)

## Conclusion

With the JSON editor in MapTiler Map Designer, it is possible to do **advanced editing or writing style JSON codes by hand**. If there is a complex or nested expression used in a map style, UI will switch to the JSON editor, where you can edit any part of your code.

## Next steps

Continue to [Map data visualization with MapTiler](https://docs.maptiler.com/guides/map-design/map-data-visualization-with-maptiler-cloud/) to learn how to create three different types of data visualizations in MapTiler: Circles, Heatmaps, and Choropleth.

## Useful links

[GL Style Specification](https://docs.maptiler.com/gl-style-specification/)