WKT (Well-Known Text)
Open BetaWKT är ett textrepresentationsformat för geometrier, som används i databaser (PostGIS, SpatiaLite) och GIS-applikationer. Enkelt och lätt att integrera.
Viktiga funktioner
Om formatet WKT
WKT (Well-Known Text) is the textual encoding of geometry from the OGC standard: POINT(37.6177 55.7558), LINESTRING(...), POLYGON((...)). It is understood by every spatial database and library — PostGIS, SpatiaLite, Shapely, JTS, GEOS — and it can be read by eye, which makes the format indispensable while debugging.
The export is taken when geometry is needed as text: to paste into an SQL query, to put into a test, to pass coordinates to someone else's system, to take a quick look at what came out of the selected area at all.
The output is a single text file in UTF-8. At the top are comments with the bounding box of the area and the coordinate system, then it goes layer by layer: a line like "-- layer: roads" with one geometry per line underneath it. Coordinates are in WGS84 (EPSG:4326) with six decimal places — that is about ten centimeters on the ground.
One important thing: WKT stores shapes only. There are no names, types or other OpenStreetMap tags in the file — if you need attributes, take GeoJSON, GeoPackage or a CSV with a WKT column.
Vilket program öppnar WKT-filer
Följande program och applikationer kan öppna, redigera och arbeta med WKT (Well-Known Text)-filer (.wkt) som exporterats från OSM2CDR:
Format specifications
- Open standard
- 3D coordinates supported
- Lossless (no quality loss)
- No attributes
- Output: 1 file
- Well-Known Text (OGC Simple Features). One geometry per line, human-readable. Direct INSERT into PostGIS / Spatialite.
Vem använder WKT-kartor
Så exporterar du WKT
Så öppnar du filen efter exporten
- PostGIS — paste the lines as they are: INSERT ... VALUES (ST_GeomFromText('POLYGON((...))', 4326)); the SRID must be specified.
- Python — from shapely import wkt, then wkt.loads(line) line by line, skipping the lines that begin with two hyphens.
- QGIS — the QuickWKT plugin pastes geometry from the clipboard onto a temporary layer; for a full-fledged layer it is easier to download GeoJSON right away.
- Tables — WKT is understood by CSV import in QGIS: "Add Delimited Text Layer", with geometry from the WKT field.
- Checking — ST_IsValid in PostGIS or shapely.is_valid: self-intersections after simplification do happen, and it is better to learn about them before loading into a database.
Populära kartor i WKT
Hämta kartexporter i WKT (Well-Known Text)
Ladda ner professionella WKT-kartor från OpenStreetMap. Direktgenerering, valfritt område.
Vanliga frågor
Jämför med andra format
Relaterade format
Ofta exporterade tillsammans
Related Articles
WKB and WKT: Geometry Formats for Developers
WKB and WKT: binary and text geometry formats. PostGIS, Shapely, GEOS. When to use which, conversion, performance, and e
formatWKT (Well-Known Text) — OGC and ISO Text Standard for Geometries in SQL
WKT is the OGC Simple Features + ISO 19125 text representation of geometries: POINT/LINESTRING/POLYGON; backbone of Post