Change coordinate systems¶

Use Convert when your data is in the wrong CRS — for example WGS 84 when you need Web Mercator.

Input data Convert Destination

A coordinate system (CRS) tells GIS software how coordinates map to the Earth. You do not need to study geodesy to change one. Pick the EPSG code your destination expects.

Before you start¶

The input should already have a CRS. If inspect shows an unknown CRS, assigning one is not a Convert control — fix the source data (include the Shapefile .prj, or set CRS in the originating software) first.

1. Add your data¶

Upload or import the dataset as usual.

2. Add Convert¶

Open Convert Properties.

Choose an Format if you also want to change file type. On Classic, you can leave Keep source format.
Set CRS. Common choices:
- EPSG:4326 — WGS 84 (latitude / longitude)
- EPSG:3857 — Web Mercator (web maps)
- EPSG:4269 — NAD83
- EPSG:27700 — British National Grid
For anything else, choose Custom EPSG… and enter a code such as EPSG:32618.

Leave Source CRS if you only want to change format.

3. Choose a Destination and Run¶

Download the result, or send it to PostGIS, GeoServer, or another Destination.

Example:

Input data
    ↓
Convert
EPSG:4326 → EPSG:3857
    ↓
GeoPackage download

What happens next?¶

Geometries are rewritten in the target CRS. Attribute fields are unchanged.

If the source CRS is missing, Convert fails with The dataset could not be reprojected because a usable CRS is missing.

If the EPSG code is not valid, you will see The target CRS is not valid.

Having trouble?¶

See Processing problems.