Multi‑map Sync (Vanilla JS) + ArcGIS + postMessage iframes

Multi‑map Sync (Vanilla JS) + ArcGIS + postMessage iframes

Type coordinates (lat, lon) or search a place; pan/zoom any map and the others stay synced. URL hash supported like #@41.7010,-73.9210,10.
Leaflet (OSM raster)CRS: EPSG:3857
MapLibre GL (vector tiles)CRS: EPSG:3857
ArcGIS JS API (topo‑vector)CRS: EPSG:3857
Child frame A — Leaflet OSM (listens to postMessage)Independent viewer
Child frame B — Leaflet OpenTopoMap (listens to postMessage)Independent viewer
Tip: you can use the postMessage pattern for any viewers you control. For third‑party sites, fall back to URL templates (if supported).