.PRJ file extension - ArcView Shapefile projections definition file
What is prj file? How to open prj files?
File type specification:
File extension prj is also associated with ArcView Shapefile projection format; the coordinate system and projection information, a plain text file describing the projection using text format.
The projection information contained in the .prj file is critical in order to understand the data contained in the .shp file correctly. Although it is technically optional, it is most often provided, as it is not necessarily possible to guess the projection of any given points. Some typical information contained in the .prj file is:
- Geographic coordinate system
- Datum
- Spheroid
- Prime meridian
- Map projection
- Units used
The ESRI Shapefile is a popular geospatial vector data format for geographic information systems software. It is developed and regulated by ESRI as a (mostly) open specification for data interoperability among ESRI and other software products. A shapefile commonly refers to a collection of files with .shp, .shx, .dbf, and other extensions on a common prefix name (e.g., "lakes.*"). The actual shapefile relates specifically to files with the ".shp" extension, however this file alone is incomplete for distribution, as the other supporting files are required.
Shapefiles spatially describe geometries: points, polylines, and polygons. These, for example, could represent water wells, rivers, and lakes, respectively. Each item may also have attributes, that describe the items, such as the name or temperature.
Updated: March 24, 2024
The default software associated to open prj file:
ArcGIS for Desktop Basic (ArcView) 
Company or developer:
Esri
ArcGIS for Desktop Basic (formerly known as ArcView) is GIS (geographic information system) application used to visualizing, managing, creating, and analyzing geographic data.
ArcGIS for Desktop Basic is a part of the ArcGIS Desktop. ArcGIS for Desktop Basic supports creation of interactive maps, spatial analysis, GIS deployment, map viewing and navigation, map printing etc.
List of software applications associated to the .prj file extension
Recommended software programs are sorted by OS platform (Windows, macOS, Linux, iOS, Android etc.)
and possible program actions that can be done with the file: like open prj file, edit prj file, convert prj file, view prj file, play prj file etc. (if exist software for corresponding action in File-Extensions.org's database).
Hint:
Click on the tab below to simply browse between the application actions, to quickly get a list of recommended software, which is able to perform the specified software action, such as opening, editing or converting prj files.
Software that open prj file - ArcView Shapefile projections definition file
Programs supporting the exension prj on the main platforms Windows, Mac, Linux or mobile. Click on the link to get more information about ArcGIS for Desktop Basic (ArcView) for open prj file action.
