How to Merge polygons while zooming out using leaflet?

Leaflet and Polygon Merging: Making Maps Zoom Smoothly

Leaflet is fantastic. Seriously, it’s the go-to open-source JavaScript library if you want to build interactive maps that actually work well on phones. But, like any powerful tool, it has its quirks. One issue I’ve run into time and again is performance when you’re dealing with tons of polygons. Imagine trying to render every single building in a sprawling city – your browser will start to sweat, and your users will get a sluggish, frustrating experience. That’s where dynamically merging polygons as you zoom out comes in. It’s a clever trick to keep things running smoothly.

Why Bother Merging Polygons?

Think about it this way: when you’re zoomed way in, seeing every individual building is super useful. You want that detail. But when you zoom out to see the whole city, do you really need to see each building? Probably not. It’s just visual clutter at that point. Merging those buildings into larger blocks or districts simplifies the map, making it faster and easier to use. It’s all about giving the user the right level of detail for the zoom level they’re at.

How to Actually Do It

Okay, so Leaflet doesn’t have a magic “merge polygons” button. Bummer, I know. But don’t worry, there are several ways to tackle this. I’ve tried a few of these myself, with varying degrees of success.