CRS detector

Not sure what coordinate reference system your data is in? Paste a .prj file for a reliable EPSG match, or paste coordinates to narrow down whether the data is geographic degrees or a projected grid in meters.

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Frequently asked questions

How do I find the CRS of a shapefile?

Open the shapefile's .prj sidecar file — it carries a WKT projection string that names the coordinate reference system exactly. Paste that string into the CRS detector to match it to an EPSG code. A shapefile without a .prj has no embedded CRS and you must recover it from metadata or the data source.

What is a .prj file?

A .prj file is the plain-text sidecar that ships alongside a shapefile's .shp, .shx and .dbf parts. It contains a WKT (well-known text) description of the coordinate reference system — datum, projection and units — so software knows how to place the geometry on the earth.

Can you detect the CRS from coordinates alone?

Only narrow it down, never pin it exactly. Coordinate ranges can tell geographic degrees (roughly ±180/±90) apart from a projected grid in metres, but many systems share the same numeric range. Treat a coordinate-only guess as a starting point and confirm it against the .prj or source metadata before reprojecting.