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WKT (Well-Known Text)

Open Beta

.wkt · text/plain

WKTは、ジオメトリのテキスト表現フォーマットで、データベース（PostGIS、SpatiaLite）やGISアプリケーションで使用されます。シンプルで統合が容易です。

今すぐWKTをエクスポート ✨ オープンベータ — 無料、制限なし

主な機能

✓テキスト形式

✓OGC標準

✓DBとの簡単な統合

✓あらゆるジオメトリ種別に対応

WKTフォーマットについて

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.

WKTファイルを開けるプログラム

次のプログラムおよびアプリケーションは、OSM2CDRからエクスポートしたWKT (Well-Known Text)（.wkt）ファイルを開き、編集し、利用できます：

💻PostGIS 💻SpatiaLite 🌎QGIS 💻Shapely (Python) 💻JTS (Java) 💻GEOS

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.

WKT地図を利用するユーザー

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データベース（PostGIS）

Geometry is pasted into SQL directly through ST_GeomFromText — with no converters and no intermediate files.

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プログラミング

Convenient material for tests and debugging: the shape is visible to the eye right in the source.

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GIS 解析

Quick exchange of geometry between GIS tools, all of which understand WKT.

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システム連携

Passing coordinates to an adjacent system that accepts plain text rather than GIS format files.

WKTのエクスポート方法

範囲を選択

osm2cdr.ruのインタラクティブ地図上で長方形またはポリゴンを描画します

WKTを選択

利用可能な127種類のエクスポートフォーマットの一覧からWKT (Well-Known Text)を選択します

エクスポート

「エクスポート」をクリックすると、1〜5分で.wktファイルを受け取れます

ダウンロード

完成したWKTファイルをダウンロードし、PostGISで開きます

エクスポート後の開き方

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.