Grids are available as lines or polygons. Lines are faster to display and easier to style. Polygons are adapted to perform spatial joins but are slower to draw.
Clic on a zone to get a list of available grids. All grids are provided as Geopackage files. Each geopackage contains 1, 5, 10 and 100km grids. 5 km grids are not a MGRS standard but are well suited for some regional scales.
Grids are also available in two datums : WGS84 (EPSG:4326) and ED50 (EPSG:4230). The most commonly used is the WGS84 version but if you want to be compatible with older european maps, you have to choose the ED50 version. A wrong choice can lead to a loss of more then 90m along the x axis and more than 200m along the y axis!
You can find other MGRS grids on https://earth-info.nga.mil (follow Coordinates Systems / Data - Warning : all grids of this source are computed with the WGS84 datum and precision is a little be less accurate).
Y. Barbier, 2021.