A browser-based Shapefile viewer that converts shapefiles to GeoJSON (WGS84) without requiring GIS software or server uploads. When a .prj file is missing, users can select the appropriate datum, which is critical for Japanese data that may use the legacy Tokyo Datum—coordinates can shift by 464 meters if the wrong datum is chosen.
A browser-based GeoJSON viewer that validates data against RFC 7946 standards, checking that bounding boxes contain their data, rings close properly, coordinates stay within valid ranges, and the right-hand rule is followed. All processing happens locally in the browser without uploading data, and validation issues are displayed visually on an interactive map.