WebGIS performance checklist

Perceived lag usually comes from tile fetching, main-thread rendering, or heavy vector work. This post is a practical checklist to narrow down bottlenecks quickly.

What to optimize first?

Start with the network and tile strategy: CDN, HTTP/2, cache headers, and sensible zoom ranges often yield the biggest wins. Then check whether the client redraws entire layers more often than needed.

For huge datasets, simplify geometry, load by zoom level, or move to vector tiles with server-side aggregation. Throttle interaction handlers to keep the main thread responsive.