Map Caching

Map caching is the pre-rendering and storage of map tiles or vector tiles so that maps load quickly and reliably under heavy use or poor networks. Raster tiles are images per zoom level; vector tiles carry geometry and attributes for client-side styling. Caches are organized in pyramids keyed by x/y/z indices and delivered via CDNs. Benefits include speed, predictable server load, and offline capability. Costs include storage, invalidation complexity, and cache staleness. Good caching strategies separate static basemaps from frequently updated operational layers and employ cache-busting via versioned URLs. For analytics, partial cache rebuilds and on-demand tiling reduce downtime. Edge cases include the antimeridian, retina displays, and multiple projections. Monitoring hit ratios and latency helps tune caches. In tiled systems, choosing an appropriate maximum zoom safeguards storage budgets without sacrificing perceived detail for the task at hand. In tiled systems, choosing an appropriate maximum zoom safeguards storage budgets without sacrificing perceived detail for the task at hand.