Coordinate tools
CRS Toolkit
Loading the CRS library…
Inspect & validate
Definition, area of use and datum shift of a CRS; optionally check a coordinate against it (range, area of use, axis order, scale distortion).
Compare & accuracy
Side-by-side definitions, the transformation path through WGS 84 with its EPSG accuracy, and how far a point moves if the two systems are confused.
Detect CRS
Find which coordinate reference systems place your coordinates inside their area of use. Projected grids repeat across zones, so give the approximate site location when you know it.
FAQ
Where do the CRS definitions come from?
From the EPSG Geodetic Parameter Dataset through PROJ. Each system’s datum shift is the best single Helmert transformation to WGS 84 for its area of use, with the accuracy EPSG publishes for it.
Can the toolkit tell which UTM zone my coordinates are in?
Not from the numbers alone: the same easting and northing are valid in every UTM zone. Enter the approximate site location and the candidates are ranked by distance from it.
Can it tell WGS 84 UTM from a local datum on the same projection?
No. Two CRSs that share a projection but use different datums produce coordinates in the same range. The toolkit groups them and shows how far apart the same point lands, so you know what is at stake when you ask the data provider.
What does the combined accuracy mean?
Coordinates move between two CRSs through WGS 84. The combined value is the root-sum-square of the EPSG accuracies of the operations on that path, an indication of how well the transformation reproduces the official one, not the accuracy of your survey.