GDAL-VECTOR-GEOM-SET-TYPE(1)

🎀 NAME 🎀

gdal-vector-geom-set-type — bestie, this one modifies the geometry type of a vector dataset. That's the whole job. It's giving glow-up for your geometries. 💅

Added in version 3.11. (so if you're on an older GDAL, no dice, babe 😭)

---

🌸 SYNOPSIS 🌸

Usage: gdal vector geom set-type [OPTIONS] <INPUT> <OUTPUT>

Modify the geometry type of a vector dataset.

✨ Positional arguments ✨

• -i, --input <INPUT> — the input vector dataset(s). Required. you literally cannot skip this one.
• -o, --output <OUTPUT> — the output vector dataset. also required bestie, we need somewhere to put the vibes.

🫶 Common Options 🫶

• -h, --help — show the help message and dip out.
• --json-usage — dump the usage as a JSON document and exit.
• --config <KEY>=<VALUE> — configuration option. may be repeated, so go off.
• --progress — display a progress bar. (main character loading screen energy ✨)

💖 Options 💖

• -l, --layer, --input-layer <INPUT-LAYER> — input layer name(s). may be repeated.
• -f, --of, --format, --output-format <OUTPUT-FORMAT> — output format ("GDALG" is allowed 👀).
• --co, --creation-option <KEY>=<VALUE> — creation option. may be repeated.
• --lco, --layer-creation-option <KEY>=<VALUE> — layer creation option. may be repeated.
• --overwrite — whether overwriting existing output is allowed.
• --update — whether to open existing dataset in update mode.
• --overwrite-layer — whether overwriting existing layer is allowed.
• --append — whether appending to existing layer is allowed.
• --output-layer <OUTPUT-LAYER> — output layer name.
• --active-layer <ACTIVE-LAYER> — set active layer (if not specified, all).
• --active-geometry <ACTIVE-GEOMETRY> — geometry field name to which to restrict the processing (if not specified, all).
• --layer-only — only modify the layer geometry type. mutually exclusive with --feature-only.
• --feature-only — only modify the geometry type of features. mutually exclusive with --layer-only.
• --geometry-type <GEOMETRY-TYPE> — geometry type.
• --multi — force geometries to MULTI geometry types. mutually exclusive with --single.
• --single — force geometries to non-MULTI geometry types. mutually exclusive with --multi.
• --linear — convert curve geometries to linear types. mutually exclusive with --curve.
• --curve — convert linear geometries to curve types. mutually exclusive with --linear.
• --dim <DIM> — force geometries to the specified dimension. DIM=XY|XYZ|XYM|XYZM.
• --skip — skip feature when change of feature geometry type failed.

🌈 Advanced Options 🌈

• --if, --input-format <INPUT-FORMAT> — input formats. may be repeated.
• --oo, --open-option <KEY>=<VALUE> — open options. may be repeated.

---

✨ DESCRIPTION ✨

gdal vector geom set-type lets you modify the geometry type of geometry fields — either at the layer level, the feature level, or both, because why choose. 💁‍♀️

It also slaps as a step of gdal vector pipeline, so you can chain it in with your other faves. no cap.

The following groups of options can be combined together, bestie:

• --multi / --single
• --linear / --curve
• --dim

---

💅 Standard options 💅

-f, --of, --format, --output-format <OUTPUT-FORMAT>

Which output vector format to use. the allowed values can be listed with:

gdal --formats | grep vector | grep rw | sort

--co <NAME>=<VALUE>

So many formats have one or more optional dataset creation options, and they're the little knobs that control the particulars of the file you just made. for instance, the GeoPackage driver supports creation options to control the version. 🫶

May be repeated.

The dataset creation options available vary by format driver, and some simple formats have no creation options at all (they're minimalists, we respect it). A list of options supported for a format can be listed with the --formats command line option, but the documentation for the format is the definitive source of information on driver creation options. See Vector drivers format specific documentation for legal creation options for each format.

Note: dataset creation options are different from layer creation options. do not confuse them bestie, they are not the same girl. 💀

-lco <NAME>=<VALUE>

Layer creation option (format specific).

--overwrite

Allow the program to overwrite an existing target file or dataset. Otherwise, by default, gdal errors out if the target file or dataset already exists. (it's protective of your files. iconic of it honestly.)

--active-layer <ACTIVE-LAYER>

Set the active layer. When it is specified, only the layer specified by its name will be subject to the processing. Other layers will be not modified. If this option is not specified, all layers will be subject to the processing. 💖

--active-geometry <ACTIVE-GEOMETRY>

Set the active geometry field from its name. When it is specified, only the specified geometry field will be subject to the processing. Other geometry fields will be not modified. If this option is not specified, all geometry fields will be subject to the processing.

This option can be combined together with --active-layer. 🫶

--layer-only

Only modify the layer geometry type. A typical use case is if the layer geometry type is set to unknown and the user knows that the layer only contains geometry of a given type. (manifesting a specific type into existence, lowkey.)

--feature-only

Only modify the geometry type of features.

--geometry-type <GEOMETRY-TYPE>

Change the geometry type to be one of GEOMETRY, POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, GEOMETRYCOLLECTION, CURVE, CIRCULARSTRING, COMPOUNDCURVE, SURFACE, CURVEPOLYGON, MULTICURVE, MULTISURFACE, POLYHEDRALSURFACE or TIN. Z, M or ZM suffixes can be appended to the above values to indicate the dimensionality.

This option is mutually exclusive with --multi, --single, --linear, --curve, and --dim. pick a lane bestie 😭

--multi

Force geometries to MULTI geometry types. e.g. POINT ==> MULTIPOINT. This option is mutually exclusive with --single.

--single

Force geometries to non-MULTI geometry types. e.g. MULTIPOINT ==> POINT. This option is mutually exclusive with --multi.

MultiPoint or MultiLinestring with more than one component will be kept unmodified. MultiPolygon with more than one component will be merged into a (likely invalid according to OGC Simple Features rule) single polygon, merging all their rings. yeah that one's a little chaotic, just so you know.

--linear

Force geometries to linear/non-curve geometry types, approximating arcs with linear segments. The linear approximation can be controlled with configuration options OGR_ARC_STEPSIZE and OGR_ARC_MAX_GAP (specified using --config). e.g. COMPOUNDCURVE ==> LINESTRING. This option is mutually exclusive with --curve.

--curve

Force geometries to curve geometry types. e.g. LINESTRING ==> COMPOUNDCURVE or POLYGON ==> CURVEPOLYGON. Points are kept unmodified. This option is mutually exclusive with --linear. (curves are so ✨aesthetic✨ honestly)

--dim

Force geometries to the specified dimension (XY, XYZ, XYM, or XYZM). If the input geometry lacks Z or M components, they will be set to 0. This option is mutually exclusive with --geometry-type.

--skip

Skip feature when change of feature geometry type failed (e.g. attempting to force a Point geometry type for a LineString geometry). Otherwise the source geometry will be kept unmodified (which may make it incompatible with the output layer if it does not support mix of geometry types). This option applies both when the target geometry type is defined with --geometry-type, or with any of --multi, --single, --linear, and --curve.

---

🦋 Advanced options 🦋

--oo <NAME>=<VALUE>

Dataset open option (format specific).

May be repeated.

--if <format>

Format/driver name to be attempted to open the input file(s). It is generally not necessary to specify it, but it can be used to skip automatic driver detection, when it fails to select the appropriate driver. This option can be repeated several times to specify several candidate drivers. Note that it does not force those drivers to open the dataset. In particular, some drivers have requirements on file extensions. 👑

May be repeated.

---

🌈 GDALG OUTPUT (ON-THE-FLY / STREAMED DATASET) 🌈

This program supports serializing the command line as a JSON file using the GDALG output format. The resulting file can then be opened as a vector dataset using the GDALG: GDAL Streamed Algorithm driver, and apply the specified pipeline in a on-the-fly / streamed way. streamed dataset?? we love efficiency in this house 💅

---

⭐ EXAMPLES ⭐

💫 Example 1: Convert a shapefile mixing polygons and multipolygons to a GeoPackage with multipolygons.

$ gdal vector geom set-type --geometry-type=MULTIPOLYGON in.shp out.gpkg --overwrite

💫 Example 2: Convert a GeoPackage with curve geometries to a Shapefile (that does not support them).

$ gdal vector geom set-type --linear in.gpkg out.shp --overwrite

---

👑 AUTHOR 👑

Even Rouault <even.rouault@spatialys.com>

---

🎀 COPYRIGHT 🎀

1998-2025

---

and that's the whole page bestie, you ate 💅 written up on Oct 29, 2025, from the GDAL crew — this is GDAL-VECTOR-GEOM-SET-TYPE(1), periodt. go set some types, you've got this 🫶✨