GeoJSON is an open standard format for encoding geographic data structures. It's widely supported by mapping libraries (Leaflet, Mapbox, Google Maps), GIS software (QGIS, ArcGIS), and databases (PostgreSQL+PostGIS, MongoDB). Converting CSV to GeoJSON bridges the gap between spreadsheet data and interactive maps, enabling you to visualize points, routes, and regions instantly.

GeoJSON strictly uses [longitude, latitude] order — not [latitude, longitude]. Longitude comes first (X-axis, -180 to 180), followed by latitude (Y-axis, -90 to 90). This is the same order used in most GIS systems (EPSG:4326). Our tool automatically arranges coordinates correctly based on your column selections, so you don't need to worry about this.

Use the Group By Column option. If your CSV has a column like track_id or route_name, rows sharing the same value will be combined into a single LineString. Use the Sort By Column option (e.g., a timestamp or sequence number) to ensure points appear in the correct order along the route.

Yes! If the first and last coordinates of a polygon group don't match, the tool automatically appends the first coordinate to close the ring. This ensures your polygons render correctly in all GeoJSON-compatible viewers. You'll see a note in the conversion summary when auto-closure is applied.

Rows where longitude or latitude values are missing, non-numeric, or out of range (lon: -180~180, lat: -90~90) are skipped during conversion. The tool reports how many rows were skipped in the conversion summary. We recommend cleaning your data before conversion to avoid unexpected results.

Absolutely! Copy the generated GeoJSON and paste it into geojson.io — a free online map viewer that renders GeoJSON instantly. You can also drag & drop the downloaded .geojson file directly onto the map. For larger datasets, try mapshaper.org.

This tool runs entirely in your browser — there's no server-side processing. It can comfortably handle CSVs with up to 50,000 rows on most devices. For very large datasets, consider splitting your CSV into smaller chunks or using command-line tools like ogr2ogr (GDAL) or csv2geojson (Node.js).

If your CSV includes an elevation/altitude column, include it in the Properties selection. However, GeoJSON geometry coordinates can optionally include a third value for elevation: [longitude, latitude, elevation]. Our current version stores elevation in properties. For 3D coordinates in the geometry itself, you may need post-processing with a script.

Common reasons: (1) The group has too few points — LineStrings need ≥2 points, Polygons need ≥3 distinct points. (2) Coordinates are invalid or out of range. (3) The row contains empty coordinate values. Check the conversion warnings for details on skipped groups and rows.

Yes! Once the page loads, all processing happens locally in your browser. No data is ever sent to any server. You can even save the page for offline use — your CSV data stays private and secure on your device.