My map has hundreds of pins and is unreadable, now what?
Cluster nearby markers into a single count that splits as you zoom, and keep rendering cheap so the map stays smooth.
Clustering turns crowds into counts
Marker clustering groups nearby points into one bubble with a count (like "24"). As the user zooms in, the cluster splits back into individual markers. Most map libraries ship a clustering add-on for this.
I am showing [number] markers on a [map library] map and they overlap into an unreadable blob. Show me how to add marker clustering so nearby points collapse into a count that splits as I zoom in.
Rendering all of them at once is the real cost
The slowdown comes from creating thousands of marker DOM nodes at once. Clustering helps because it renders far fewer elements. You can also render only the markers inside the current viewport, so off-screen points never get drawn.
My [map library] map lags when I load all markers at once. Should I solve this with clustering, viewport-only rendering, or both for [my number of points], and how do I measure which helps?
Cluster nearby markers into a single count that splits on zoom, and render only the markers in view. The map stays readable and fast even with hundreds of points.
Additional Resources
Explore these carefully curated resources to deepen your understanding and practice the concepts covered in this lesson.