Viewshed Calculator
Upload a .tif/.tiff elevation model (DEM), click the map (or type coordinates) to place an observer, and see which cells are visible from that point — accounting for terrain occlusion.
Private by design. Your file is processed entirely in your browser (R via WebAssembly) — it’s never uploaded to any server, including ours. Nothing to configure, nothing to trust: the code never gets the chance to see your data.
The code itself isn’t shown here — it’s a fixed, non-editable computation using terra::viewshed() underneath. Want to see it built up step by step (and read why this tool runs on R, not Python)? Read Viewshed: What’s Visible from Here.
First run loads the R engine — expect 1-3 minutes (R’s WebAssembly build is noticeably slower to start than this site’s Python tools). Instant after that, and again each time you come back to this page.
Fourth and last tool in the Raster family. Read the companion article for the same computation built up one cell at a time — including why this is the one tool on this site that runs on R, with Python shown only as a reference (not runnable here).