Coverage and file sizes

GML

• A zipped file comprising a national set.

• The size of the zipped file is approximately 568 MB.

• The zipped file contains 52 GML files, which each contain up to three feature types (see Product chunking below for more information).

• The size of each GML file ranges from 19 KB to 870 MB.

• The data is not encrypted.

ESRI shapefile

• A zipped file comprising a national set.

• The size of the zipped file is approximately 566 MB.

• The product is split into 100 km² tiles (see Product chunking below for more information).

• The zipped file contains up to 156 shapefiles.

• Each shapefile contains a single feature type for a 100 km² area.

• The data is not encrypted.

GeoPackage

• A zipped file comprising a single national GeoPackage file.

• The size of the zipped file is approximately 973 MB.

• The GeoPackage file contains three individual layers, one for each feature type, each with national coverage.

• The data is not encrypted.

Vector tiles

• A zipped file comprising a single national MBTiles file.

• The size of the zipped file is approximately 1.3 GB.

• The MBTiles file contains a full set of national vector tiles.

• The data is not encrypted.

Product chunking

Ordnance Survey divides Great Britain into squares of 100 km by 100 km. Each of these squares has a unique two-letter reference, for example, TG in the image below.

To ensure that file sizes are manageable, GML and shapefile files are supplied as 100 km-by-100 km tiles.

UK map showing 100 km-by-100 km tiles used to chunk up the OS Open Roads GML and shapefile data.

The tiles are not cut at the tile edge of the zones. Consequently, features that extend across the edge of the tiles are supplied in more than one file. Users need to remove the duplicate features once the data has been translated. Each feature has a unique identifier (id) for this purpose.