Reproject Geospatial Data Online — Change CRS for Shapefiles, GeoTIFF and More
Free browser-based reprojection tools for vector and raster geospatial formats. Convert any GeoJSON, Shapefile, GeoPackage, or GeoTIFF to a new coordinate reference system, or assign a CRS to data missing projection metadata — all processed locally without uploading to a server.
What is reprojection?
Reprojection converts spatial data from one coordinate reference system (CRS) to another. Every geospatial dataset is stored in a CRS that defines how coordinates relate to locations on Earth. When data from different sources uses different CRS, features appear misaligned or at wrong positions — reprojection fixes this by transforming all coordinates to a common system.
Common reprojection scenarios include converting from a local national grid (e.g., British National Grid EPSG:27700) to WGS 84 (EPSG:4326) for web mapping, from geographic coordinates to a projected system for area or distance calculations, or from one UTM zone to another.
Assigning a CRS is different — it records projection metadata on a file that lacks it, without transforming any coordinate values. Use this when data was exported without a .prj file or when the CRS is known but missing from the file.
Common use cases
Convert to WGS 84 for web mapping
Reproject data from any national or local CRS to WGS 84 (EPSG:4326) or Web Mercator (EPSG:3857) for use in Leaflet, Mapbox, or Google Maps.
Align datasets from different sources
When overlaying data from multiple agencies that use different national grids, reproject all layers to a common CRS to ensure features align correctly.
Enable accurate area and distance calculations
Reproject data to an equal-area or equidistant projection (such as UTM or Albers) before calculating areas, lengths, or buffers in a GIS.
Fix missing projection metadata
Use the Assign CRS tool to add projection information to a Shapefile that is missing its .prj file, or to a raster that was exported without embedded metadata.
How to use
- 1
Choose the tool — select the reprojection tool for your file format, or the Assign CRS tool if your file is missing projection metadata.
- 2
Upload your file — drop the file onto the upload zone.
- 3
Select the target CRS — search by EPSG code or name (e.g., "27700" for British National Grid, "4326" for WGS 84).
- 4
Download the result — the reprojected file is returned in the same format as the input.
Available tools
| Tool | What it does |
|---|---|
| Reproject Shapefile | Change the CRS of a Shapefile and update the .prj file. |
| Reproject Vector | Reproject any GDAL-supported vector format to a new CRS. |
| Reproject GeoTIFF | Warp a GeoTIFF raster to a new CRS using gdalwarp. |
| Assign CRS | Set projection metadata on a file without transforming coordinates. |
Frequently asked questions
What is an EPSG code?
An EPSG code is a numeric identifier for a specific coordinate reference system. For example, EPSG:4326 is WGS 84 geographic, EPSG:3857 is Web Mercator, and EPSG:27700 is British National Grid. Search by code or CRS name in any of these tools.
What is the difference between reprojecting and assigning a CRS?
Reprojecting transforms coordinate values — every vertex in the dataset is mathematically moved to its correct position in the target CRS. Assigning a CRS only updates the metadata — it does not change any coordinate values. Use assign CRS when the data already has the right coordinates but is missing the .prj file or CRS metadata.
What happens if I reproject to a CRS that does not cover my data?
Projections are designed for specific geographic areas. Reprojecting data far outside the intended region of a projected CRS can cause severe distortion or projection failures. Always choose a CRS appropriate for the geographic extent of your data.
Can I reproject a raster with multiple bands?
Yes — the Reproject GeoTIFF tool handles all bands simultaneously. The pixel values and band composition are preserved; only the coordinate positions and spatial extent are transformed.
What resampling method is used when reprojecting a raster?
The Reproject GeoTIFF tool uses bilinear resampling by default, which is appropriate for continuous data such as elevation or imagery. For categorical rasters (land cover classification), nearest-neighbour resampling avoids creating interpolated class values.