How do you optimize the performance of Mapbox GL JS for large datasets?

1 Use clustering

Clustering is a technique that groups nearby points into clusters based on zoom level and distance. This reduces the number of features rendered on the map, improves loading speed, and avoids overlapping labels. Mapbox GL JS provides a built-in option to enable clustering for GeoJSON sources, as well as a cluster layer type to style and interact with clusters.

2 Use data-driven styles

Data-driven styles are a way to dynamically change the appearance of features based on their properties or expressions. For example, you can use data-driven styles to color points by category, size circles by value, or filter features by zoom level. Data-driven styles can help you create more informative and responsive maps, as well as reduce the number of layers and sources needed.

3 Use simplified geometries

Simplified geometries are versions of your original data that have fewer vertices and less detail, but still preserve the essential shape and features. Simplifying geometries can reduce the file size and complexity of your data, which can improve the performance and rendering of your map. You can use tools like Mapshaper, Tippecanoe, or Turf.js to simplify your geometries before adding them to your map.

4 Use vector tiles

Vector tiles are a format that splits your data into small tiles that are delivered on demand and rendered on the client side. Vector tiles have several advantages over raster tiles or GeoJSON files, such as: smaller file size, faster loading, smoother zooming, and more styling options. Mapbox GL JS supports vector tiles from various sources, including Mapbox, Tileserver GL, or your own custom tilesets.

5 Use web workers

Web workers are a feature of JavaScript that allows you to run scripts in the background without blocking the main thread. Web workers can help you perform computationally intensive tasks, such as parsing, filtering, or transforming data, without affecting the responsiveness and interactivity of your map. Mapbox GL JS uses web workers internally to handle tile loading and rendering, but you can also use your own web workers to process your data before adding it to your map.

6 Use map events and methods

Map events and methods are ways to control and interact with your map programmatically. For example, you can use map events to listen for user actions, such as zooming, panning, or clicking, and respond accordingly. You can also use map methods to manipulate the map state, such as setting the center, zoom, bearing, or pitch. By using map events and methods, you can create more dynamic and user-friendly maps, as well as optimize the performance and visibility of your data.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?