Standard tile layer
OpenStreetMap Carto, osm-carto
Baclaran, Paranaque and Pasay Rotunda, Pasay
|Authors:||Andy Allan and|
|Tiles license:||CC-BY-SA 2.0|
Bug reports can be raised GitHub account.(for the style itself, e.g. rendering problems of specific object classes) or (for actual tiles rendering on OSM.org, caching etc.) – both need a login with a
OSM servers deployment
Low and medium zoom tiles (z0–z12) are usually re-rendered only when a new OSM Carto version is being deployed and on the first Sunday of each month. Database schema changes should not be requested more often than 1–2 times a year (probably combined with major PostgreSQL release).
If using the Standard tiles from openstreetmap.org tile servers in other applications, you must follow the Tile usage policy.
Since this style is feature-rich, the short map key included on the OSM.org homepage is very limited. See Standard tile layer/Key and its subpages for the most complete and up to date legend version:
- 2012 – porting XML version to CartoCSS (start of the OSM Carto)
- 2013 – OSM tileservers deployment
- 2014 – rewrite of buildings code
- 2015 – road style change, SVG icons
- 2016 – better rendering of placenames
- 2017 – water color, mid zoom improvements, database schema change
- 2018 – office and healthcare keys rendering, new POI color categories
The style is designed as a general-purpose map of the world, so for example:
- special objects (like seamarks or railway details) will not be rendered
- labels are rendered with a name=* value (whatever it contains for a given object), so it's not displaying English names all over the world
- there are no country-specific symbols (like for example road shields or subway/metro signs), they all have a uniform look
While OpenStreetMap Carto tries to show many different objects, it's not possible to render everything stored in a database, so opt-in selection is made.
for some zoom levels are defined.
Mapnik and CartoCSS
OpenStreetMap Carto tiles are rendered using the Mapnik toolkit. That being said, OpenStreetMap Carto and Mapnik are not the same thing! Mapnik is a map rendering library used for many map stylesheets (including OpenStreetMap Carto).
CartoCSS is used to pre-process the stylesheet into Mapnik XML format (since August 2013).
This style has multiple layers. For example, names of waterways are rendered over waterways, shops are rendered over buildings, tunnels are rendered over buildings, roads are rendered over landcover, etc.
The remaining question is how objects are rendered within layer. For some cases collisions are not allowed, and objects that would cover already rendered object from given layer are not rendered. It is done for example for cities, where labels for smaller ones that would collide with label for a larger one are not rendered.
Landcover areas are ordered by area, with smaller ones later, and collisions are allowed. It means that for a given layer smaller areas will cover larger ones.
There is also a separate overlay layer containing for example tree symbols for forest landcover, that is rendered over landcover fill.
- area covered by small landuse=forest and large landuse=residential
- forest fill will be rendered over residential fill and cover it, later forest overlay will be rendered over that
- area covered by large landuse=forest and small landuse=residential
- residential fill will be rendered over forest fill and cover it, later forest overlay will be rendered over that
OpenStreetMap Carto uses as its standard database PostgreSQL with PostGIS geospatial extension and is named "gis". It is derived from the OSM database, but does not store the full dataset – only the rendering-related elements are available. Since v4.0.0, OpenStreetMap Carto uses the PostgreSQL hstore (extension and data type) and is pre-processed with by the osm2pgsql tool.
General project configuration is included in(YAML). There are defined so called "layers", which include mainly SQL statements selecting the objects, while actual styling is done in multiple MSS files.
Roads code is very complex and is partially generated by the helper scripts.
Icons and patterns
Icons are pixel-aligned vector images (SVG), generally based on 14 px matrix. While most of them are monochrome and their rendering color is defined in the MSS files, some of the icons have more than one color; in the latter cases, the colors are defined in the vector file itself. Halftones might be used.
Some patterns are also done as vector images, but if they are still raster images (PNG), they are derived from vector elements and the process is, so it should be easy to migrate to a vector format when possible.
Noto font is used if possible, with DejaVu Sans, Hanazono and Unifont used as fallbacks.
Rendering coastline on openstreetmap.org is described here: Coastline#Rendering in Standard tile layer on openstreetmap.org.
Contributing and installing
You can set up a copy of the OpenStreetMap Carto rendering stylesheets for yourself. For more technical information, including setup instructions, seeon GitHub:
- Contribution guidelines are documented .
- One can set a simple for testing.
- Some have been selected for getting started with the process.
If you still don't know where to start, just ask for the assistance (for example in the ticket comments).
More experienced developers are also very welcomed. Some complex tasks that need attention are:
Forks and independent deployments
OpenStreetMap Carto is used as a base for other map style rendering forks, especially:
- German osm-carto style (does also contain a branch with a localized version of OpenStreetMap Carto)
- (before osm-carto)
Vector-based solutions and testing:
There is also a separate project called OpenGeofiction (OGF), which uses OSM tools – including osm-carto as default style – for creating maps of fictional places.
- Topic on OSM forum
- OpenStreetMap Carto Tutorials – unofficial documentation (by Ircama)
- – independent Docker environment (by OnkelTem)
- (by Lukas Sommer)
- Pre-rendered low-zoom tiles (by Paul Norman)
- check https://osm.org, see git-chef line 109 (109 :revision => "vx.xx.x",) and current used carto-version on
- Timelapse videos of changes in osm-carto 2012–2016 (by Michael Glanznig)
- Custom map style (1) - tweaking the standard OpenStreetmap style for the old, pre-2012 XML format (by Volker Schatz)
- OpenStreetMap Carto Complexity (Paul Norman blog, 2015)
- OpenStreetMap-Carto – a look back at the last year (Christoph Hormann blog, 2017)
- OpenStreetMap-Carto – a look into the future (Christoph Hormann blog, 2017)
- Adding a change to "OSM Carto" (Andy Townsend diary, 2017)
- Andy Allan talks: SoTM US 2013, SoTM EU 2014, SoTM US 2015
- Rory McCann talk on SoTM 2016 ("Converting a regular carto project to vector tiles: OSM-carto case study")
- Paul Norman talk on SoTM 2017