Core operations on OpenStreetMap geometry: buffers, hulls, intersections and differences, simplification, reprojection and summary counts. Every analysis starts here — prepare, clip, merge, count. Everything runs inside the loaded PostGIS database, so there is nothing to download into a desktop GIS.
Builds polygons at a given distance in metres on the ground around every feature of the chosen layer. The radius is recomputed for the latitude of the bounding box centre: at the edges of the largest bounding box it differs by no more than 3%, and by a fraction of a percent on a small one.
Returns one point per feature: either the centre of mass or a point guaranteed to lie inside — for polygons of complex shape the second option is the reliable one.
Clips the features of a layer with an arbitrary polygon passed in the request as GeoJSON. The output holds only the parts that fall inside the outline.
Builds a hull around all features of the layer — convex or concave. This is how you get the boundary of the actual extent of the data.
Merges the touching polygons of a layer into single areas and removes the internal boundaries.
Thins out the vertices of lines and polygons while preserving topology; the tolerance is set in metres. Needed for light exports and small scales.
Returns the features of a layer nearest to the given point together with the distance to each one; the number of features is set by limit.
Clicking the map sets a point: Point.
Computes a set of urban metrics for the main bounding box and for a second one (bbox_b) and returns them side by side — for comparing districts or cities.
Splits the area into cells of influence around point features: every cell is closer to its own point than to any other.
Finds the features of a layer nearest to a given point (or to the centre of the bounding box) and returns straight-line distances on the ground in metres, sorted in ascending order.
Clicking the map sets a point: from_point.
Returns the geometry where the features of two layers intersect — what falls into both A and B.
Merges the geometries of a layer into one; with group_by set, separately for each value of the attribute.
Subtracts from the features of layer A everything that is covered by layer B.
Builds lines offset from the originals (usually roads) by a given distance: centrelines, setbacks, corridor edges.
Works out which features of layer A are related to features of layer B by the chosen type of relation and returns a summary of those links in numbers.
Measures what share of a circle of a given radius around a point is closed off by buildings. An indicator of spatial enclosure estimated from OSM building geometry, not a field survey.
Clicking the map sets a point: point.
Counts the features of a layer inside the bounding box and computes the total area or length together with basic statistical summaries.
Cuts the area into a regular grid and counts the features of a layer in each cell — a ready base for a choropleth map.
Converts the features of a layer into another coordinate system by EPSG code; the attributes are left unchanged.
The input is a rectangular bounding box in WGS84 plus one of nine data layers; some tools also take a point. The output is GeoJSON, JSON metrics or a GeoTIFF.
| Layer | What it holds |
|---|---|
| buildings | buildings |
| roads | roads and streets |
| poi | points of interest: services, shops, tourism |
| water | water bodies |
| green_areas | green areas: parks, forests, lawns |
| railways | railways |
| boundaries | administrative boundaries |
| landuse | land use |
| waterways | waterways |
Every tool in the section is free. The bounding box may cover up to 100 km². Rate limits are 10 requests per minute per tool run and 30 requests per minute for reading the catalogue. Without signing in you get up to 10 successful calculations a day; after that the service asks you to register and answers 402 with the code login_required. A box larger than the allowed area is also 402, and an unknown tool id is 404.