WKT to GeoJSON Converter
Converts a text file with WKT geometries (one per line) to GeoJSON with GDAL.
Upload a .wkt or .txt file with one geometry per line. Each line becomes a feature with the attribute line (line number). EWKT SRIDs are used as coordinate system; without SRID the GeoJSON gets no crs member and is read as WGS84.
Drag a file here to convert, or select file
Accepted: .wkt, .txt · max. 50 MB
What the converter does
- The file must contain one geometry per line as WKT (e.g. POINT (7 50)) or EWKT with SRID (SRID=25832;POINT (356000 5645000)). Empty lines are ignored; other lines are skipped and counted in the report.
- GDAL has no driver for plain WKT text files. The worker therefore writes the lines into a CSV with the columns line and WKT, and GDAL's CSV driver reads the geometry from there. The output has an attribute line with the line number from your file.
- An SRID from EWKT becomes the coordinate system (-a_srs EPSG:<SRID>). Lines with different SRIDs are refused; upload one file per SRID.
- Without SRID no coordinate system is assigned. A GeoJSON without crs member is read as WGS84 longitude/latitude, so WKT in metres needs an SRID.
- The report below the upload shows layers and features read and written, skipped layers with the reason, GDAL's warnings and the exact commands.
GDAL command the worker runs
wkt_csv/input.csv is the CSV the worker writes from your lines (columns line and WKT). For EWKT with SRID=25832 the worker adds -a_srs EPSG:25832.
Tested with
| Test file | Result |
|---|---|
| 4 lines: POINT, LINESTRING, POLYGON, MULTIPOINT | 4 of 4 features, all 4 geometry types, attribute line 1 to 4 |
| 2 EWKT lines with SRID=25832 | 2 of 2 points, coordinate system EPSG:25832 |
| 4 non-empty lines: a comment, a POINT, plain text, a LINESTRING | 2 features; report: 2 lines without WKT geometry skipped |
| EWKT with SRID 25832 and SRID 4326 mixed | Refused (HTTP 422) with the message that the lines use different SRIDs |
Tested on 24 Sep 2026 with the worker code of this site and GDAL 3.10.3 (conda-forge build on Windows). The worker image runs the Debian build of the same GDAL version; the live worker was not part of these tests.
Limits
- Upload limit: 50 MB per file.
- Each geometry must be on one line; a geometry spread over several lines is not read correctly.
- Each GDAL step may run for up to 240 seconds; a longer run is stopped with an error message.
Frequently Asked Questions
My WKT is in UTM. What do I have to do?
Put SRID=<EPSG code>; in front of each line (EWKT), e.g. SRID=25832;POINT (356000 5645000). The worker then assigns that coordinate system. Without SRID the GeoJSON is read as longitude/latitude.
What happens to my file?
Your browser uploads it directly to the GDAL worker on Fly.io (region Frankfurt). The worker converts it in a temporary folder and deletes the folder after sending the result, or immediately if the conversion fails. Files are not stored permanently.