How Shapefile works
A single "shapefile" is really a bundle: the mandatory .shp (feature geometry), .shx (a shape index for fast seeking), and .dbf (a dBASE table of attributes), usually alongside a .prj (coordinate system) and sometimes a .cpg (attribute encoding). It is the lingua franca of desktop GIS and is read by virtually every tool, from ArcGIS and QGIS to GDAL/OGR. Its age shows in several hard limits: DBF attribute field names are truncated to 10 characters, each file component is capped at 2 GB, every file holds a single geometry type, and attribute types are constrained to what DBF supports (limited-width text, numbers, dates, and booleans). For predictable, fail-closed imports, GeoConvert accepts inline dBASE III (0x03) C/N/F/L/D fields; newer dBASE/VFP variants and memo or binary fields are rejected.
What are .shp, .shx, .dbf and .prj files?
A Shapefile is a coordinated set of files with the same base name. The .shp, .shx and .dbf files are required; .prj and .cpg are technically optional but prevent coordinate-system and text-encoding ambiguity.
| File extension | Status | Purpose |
|---|---|---|
| .shp | Required | Stores feature geometry: points, lines or polygons. |
| .shx | Required | Indexes geometry records so software can locate features efficiently. |
| .dbf | Required | Stores the attribute table, with one record corresponding to each feature. |
| .prj | Recommended | Describes the coordinate reference system as WKT so the layer is positioned correctly. |
| .cpg | Recommended | Declares the character encoding used by text fields in the .dbf table. |
If a Shapefile will not open, first confirm that .shp, .shx and .dbf share exactly the same base name and remain in one folder. If the layer opens in the wrong place, recover the correct .prj or identify and assign the source CRS before reprojecting—do not guess WGS 84.
Coordinate systems and reprojection
The coordinate reference system lives in the optional .prj sidecar as a WKT (well-known text) string. When the .prj is absent the CRS is genuinely unknown and consumers typically fall back to assuming WGS84, which can silently misplace data that was in another projection.
Compare Shapefile with other GIS formats
Convert Shapefile to another format
Choose a conversion below for the online converter, format-specific caveats, and step-by-step instructions for Shapefile.
Convert files to Shapefile
Frequently asked questions
- What file extension does Shapefile use?
- Shapefile uses .shp (+ .shx, .dbf, .prj).
- Does Shapefile store a coordinate system?
- The coordinate reference system lives in the optional .prj sidecar as a WKT (well-known text) string. When the .prj is absent the CRS is genuinely unknown and consumers typically fall back to assuming WGS84, which can silently misplace data that was in another projection.
- Can I convert Shapefile online?
- Yes. GeoConvert can read or write Shapefile in your browser for the conversion paths listed above, without uploading free-tier files to a server.