Open a shapefile online

What a shapefile is

The shapefile is Esri’s file format for map data, used by GIS software, government open-data portals, surveyors and planners. One shapefile is several files with the same name: the .shp file holds the shapes (points, lines or areas), the .shx file an index, the .dbf file the attributes (a table with one row per shape), the .prj file the coordinate system and, often, a .cpg file the text encoding of the attributes.

Because it is several files, shapefiles are usually sent as a ZIP archive. Map data from Google Earth opens in the KML viewer, GPS tracks in the GPX viewer.

Why it won’t open

No ordinary program opens a shapefile: it needs GIS software such as QGIS or ArcGIS. The .shp file alone has no attributes and no coordinate system, and the coordinates are often in a national or local projection (meters, not degrees), so even a program that reads the shapes may put them in the wrong place.

What this viewer does

• Reads shapefiles from a ZIP or as separate files, also very large ones, record by record.
• Shows points, lines and areas (with their holes) on a map, one layer per shapefile.
• Converts the coordinates from the projection in the .prj file (UTM, state plane, national grids and hundreds more) to longitude and latitude.
• Shows the attribute table with every field, in the text encoding the .cpg file or the table states.
• Lists every shape, searches them by attributes, and shows each shape’s details.
• Converts to KML, GeoJSON, GPX, CSV, Excel and a new shapefile in longitude/latitude (paid).

Coordinate systems and text encodings

• The .prj file says how the coordinates are measured. The viewer converts them to longitude and latitude (WGS 84), as every web map and GPS uses. When the .prj names a datum but not the shift to WGS 84, positions can be off by up to tens of meters, and by several hundred for some older datums.
• Without a .prj file, coordinates that look like longitude and latitude are shown as such; others cannot be placed on a map. The attribute table and the Excel and CSV exports still work.
• Text encoding: attributes are read in the encoding the .cpg file names (UTF-8, Windows-1252 and other code pages), else the one the table’s header states; when neither says, the viewer checks whether the text is UTF-8 and says that it guessed.

Converting a shapefile to KML, GeoJSON or CSV

Every conversion runs in this page and keeps every feature:

• GeoJSON: one feature collection with every attribute, the standard format of web maps and GIS tools.
• KML for Google Earth: one folder per layer, the attributes as extended data.
• GPX for GPS devices and sports apps: points become waypoints and lines become tracks, with their elevations and times. GPX keeps only names and descriptions, and has no areas: an area becomes a track along its edge.
• CSV: one row per feature with latitude and longitude for points, the geometry of any feature as WKT and every attribute; or one row per point of every line, with elevation and time.
• Excel: the attribute table, one sheet per layer.
• Shapefile (ZIP) for GIS software: one set of .shp, .shx, .dbf, .prj and .cpg files per kind of geometry (points, lines, areas), in longitude/latitude (WGS 84), attributes in UTF-8. Field names are cut to the 10 characters the format allows, and text to 254 bytes. A shapefile written here is 2D: elevations and times are not kept.
• All layers in one file, or one file per layer in a ZIP. Styles (colors, icons, line widths) are not converted.

What it does not do

• 3D surfaces (multipatch shapes) are counted but not shown; measure values (M) are not read.
• Memo fields, kept in a separate .dbt file, are not read.
• It does not edit the files.
• It does not open files over 4 GB (.shp, .dbf), 2 GB (KMZ, ZIP), 1 GB (KML, GPX) or 160 MB (GeoJSON), or more than 1 million features and 12 million points in all.

The background map

The map is drawn from the file alone, on a plain background, without contacting anyone. If you press “Show background map”, your browser loads map images from an independent map tile service. That service then receives the usual connection data (your IP address and browser) and which map tiles are shown, so the area and the zoom level you look at; it never receives your file, its name or its contents. “Hide background map” goes back to the plain view; the choice is not kept when you leave or reload the page. The privacy policy says more.

Other ways to open a shapefile

• QGIS, a free GIS program for Windows, Mac and Linux: drag the .shp or the ZIP onto the map.
• ArcGIS, if you have a license.

Your files stay on your device

Map files often say where people live, work or travel. Here the files are read by code running in your browser; no code on the page sends them, their names or anything in them anywhere, not even to our own domain. The conversions are made in the page too.

Esri and ArcGIS are trademarks of Esri. The shapefile format is described in Esri’s published technical description. Other names belong to their owners and are used only to describe file formats and programs. CantOpen is not affiliated with or endorsed by any of them.