GDAL-VECTOR-BUFFER(1)                GDAL                GDAL-VECTOR-BUFFER(1)

NAME
       gdal-vector-buffer - Compute a buffer around geometries of a vector
       dataset

       Added in version 3.12.


SYNOPSIS

          Usage: gdal vector buffer [OPTIONS] <INPUT> <OUTPUT> <DISTANCE>

          Compute a buffer around geometries of a vector dataset.

          Positional arguments:
            -i, --input <INPUT>                                  Input vector datasets [required] [not available in pipelines]
            -o, --output <OUTPUT>                                Output vector dataset [required] [not available in pipelines]
            --distance <DISTANCE>                                Distance to which to extend the geometry. [required]

          Common Options:
            -h, --help                                           Display help message and exit
            --json-usage                                         Display usage as JSON document and exit
            --config <KEY>=<VALUE>                               Configuration option [may be repeated]
            -q, --quiet                                          Quiet mode (no progress bar or warning message) [not available in pipelines]

          Options:
            -l, --layer, --input-layer <INPUT-LAYER>             Input layer name(s) [may be repeated] [not available in pipelines]
            -f, --of, --format, --output-format <OUTPUT-FORMAT>  Output format ("GDALG" allowed) [not available in pipelines]
            --co, --creation-option <KEY>=<VALUE>                Creation option [may be repeated] [not available in pipelines]
            --lco, --layer-creation-option <KEY>=<VALUE>         Layer creation option [may be repeated] [not available in pipelines]
            --overwrite                                          Whether overwriting existing output dataset is allowed [not available in pipelines]
            --update                                             Whether to open existing dataset in update mode [not available in pipelines]
            --overwrite-layer                                    Whether overwriting existing output layer is allowed [not available in pipelines]
            --append                                             Whether appending to existing layer is allowed [not available in pipelines]
                                                                 Mutually exclusive with --upsert
            --output-layer <OUTPUT-LAYER>                        Output layer name [not available in pipelines]
            --skip-errors                                        Skip errors when writing features [not available in pipelines]
            --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)
            --endcap-style <ENDCAP-STYLE>                        Endcap style.. ENDCAP-STYLE=round|flat|square (default: round)
            --join-style <JOIN-STYLE>                            Join style.. JOIN-STYLE=round|mitre|bevel (default: round)
            --mitre-limit <MITRE-LIMIT>                          Mitre ratio limit (only affects mitered join style). (default: 5)
            --quadrant-segments <QUADRANT-SEGMENTS>              Number of line segments used to approximate a quarter circle. (default: 8)
            --side <SIDE>                                        Sets whether the computed buffer should be single-sided or not.. SIDE=both|left|right (default: both)

          Advanced Options:
            --if, --input-format <INPUT-FORMAT>                  Input formats [may be repeated] [not available in pipelines]
            --oo, --open-option <KEY>=<VALUE>                    Open options [may be repeated] [not available in pipelines]
            --output-oo, --output-open-option <KEY>=<VALUE>      Output open options [may be repeated] [not available in pipelines]
            --upsert                                             Upsert features (implies 'append') [not available in pipelines]
                                                                 Mutually exclusive with --append

DESCRIPTION
       gdal vector buffer computes a POLYGON or MULTIPOLYGON that represents
       all points whose distance from a geometry/geography is less than or
       equal to a given distance. A negative distance shrinks the geometry
       rather than expanding it. A negative distance may shrink a polygon
       completely, in which case POLYGON EMPTY is returned. For points and
       lines negative distances always return empty results.

       See the PostGIS ST_Buffer docs for additional graphical illustrations
       of the effect of the different parameters.

       The output dataset is always written as MULTIPOLYGON, even when the
       input contains only simple POLYGON geometries.  Note that negative
       buffer distances may also produce MULTIPOLYGON results.

       Using a buffer distance of 0 can sometimes repair invalid geometries,
       but the recommended approach is to use gdal vector make-valid for
       reliable geometry validation and repair.

       This command can also be used as a step of gdal vector pipeline.

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.

       NOTE:
          This command requires a GDAL build against the GEOS library.

PROGRAM-SPECIFIC OPTIONS

       --distance <DISTANCE>
              Radius of the buffer around the input geometry.  The unit of the
              distance is in georeferenced units of the source layer.

       --endcap-style round|flat|square
              Specifies the end cap style of the generated buffer.  Default is
              round.
                [image] Buffered lines with endcap-style=round,
                endcap-style=flat and endcap-style=square.UNINDENT

       --join-style round|mitre|bevel
              Sets the join style for outside (reflex) corners between line
              segments.  Default is round.
                [image] Buffered lines with join-style=round, join-style=mitre
                and join-style=bevel.UNINDENT

       --input-layer <NAME>
              Specifies one or more layer names to read and process. By
              default, all layers will be read and processed. To read and
              write all layers but only process a subset, use --active-layer.

       --mitre-limit <MITRE-LIMIT>
              Sets the limit on the mitre ratio used for very sharp corners.
              This option only applies when join-style=mitre is used.

              Default is 5.
                [image] Lines with a distance=2 buffer, and mitre-limit=5 on
                the left, and mitre-limit=1 on the right.UNINDENT

                The mitre ratio is the ratio of the distance from the corner
                to the end of the mitred offset corner.  When two line
                segments meet at a sharp angle, a miter join will extend far
                beyond the original geometry.  (and in the extreme case will
                be infinitely far.)  To prevent unreasonable geometry, the
                mitre limit allows controlling the maximum length of the join
                corner.  Corners with a ratio which exceed the limit will be
                beveled.

       --output-layer <NAME>
              Name of the layer to which output should be written. If not
              specified, the output layer will have the same name as the input
              layer.

       --quadrant-segments <QUADRANT-SEGMENTS>
              Sets the number of line segments used to approximate an angle
              fillet in round joins.

              This determines the maximum error in the approximation to the
              true buffer curve.  The default value of 8 gives less than 2%
              max error in the buffer distance.  For a max error of < 1%, use
              QS = 12.  For a max error of < 0.1%, use QS = 18.  The error is
              always less than the buffer distance (in other words, the
              computed buffer curve is always inside the true curve).
                [image] Buffered points with quadrant-segments=4 and
                quadrant-segments=20.UNINDENT

       --side both|left|right
              Sets whether the computed buffer should be single-sided or on
              both sides (default).

              left indicates that the buffer is generated on the left-hand
              side of the line, and right indicates that the buffer is
              generated on the right-hand side of the line, determined by the
              order of the line's vertices (i.e., the direction in which the
              line is drawn).

              Single-side buffering is only applicable to LINESTRING geometry
              and does not affect POINT or POLYGON geometries, and the end cap
              style is forced to square.
                [image] Buffered lines with  side=both, side=left and
                side=right.UNINDENT

STANDARD OPTIONS

       --append
              Whether appending features to existing layer(s) is allowed.
              This also creates the output dataset if it does not exist yet.

       --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.

       --co, --creation-option <NAME>=<VALUE>
              Many formats have one or more optional dataset creation options
              that can be used to control particulars about the file created.
              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. 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 that dataset creation options are different from layer
              creation options.

       --if, --input-format <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.

       --lco, --layer-creation-option <NAME>=<VALUE>
              Many formats have one or more optional layer creation options
              that can be used to control particulars about the layer created.
              For instance, the GeoPackage driver supports layer creation
              options to control the feature identifier or geometry column
              name, setting the identifier or description, etc.

              May be repeated.

              The layer creation options available vary by format driver, and
              some simple formats have no layer creation options at all. 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 that layer creation options are different from dataset
              creation options.

       --oo, --open-option <NAME>=<VALUE>
              Dataset open option (format specific).

              May be repeated.

       -f, --of, --format, --output-format <OUTPUT-FORMAT>
              Which output vector format to use. Allowed values may be given
              by gdal --formats | grep vector | grep rw | sort

       --output-open-option, --output-oo <NAME>=<VALUE>
              Added in version 3.12.


              Dataset open option for output dataset (format specific).

              May be repeated.

       --overwrite
              Allow program to overwrite existing target file or dataset.
              Otherwise, by default, gdal errors out if the target file or
              dataset already exists.

       --overwrite-layer
              Whether overwriting the existing output vector layer is allowed.

       --skip-errors
              Added in version 3.12.


              Whether failures to write feature(s) should be ignored. Note
              that this option sets the size of the transaction unit to one
              feature at a time, which may cause severe slowdown when
              inserting into databases.

       --update
              Whether to open an existing output dataset in update mode.

       --upsert
              Added in version 3.12.


              Variant of --append where the OGRLayer::UpsertFeature()
              operation is used to insert or update features instead of
              appending with OGRLayer::CreateFeature().

              This is currently implemented only in a few drivers: GPKG --
              GeoPackage vector, Elasticsearch: Geographically Encoded Objects
              for Elasticsearch and MongoDBv3 (drivers that implement upsert
              expose the GDAL_DCAP_UPSERT capability).

              The upsert operation uses the FID of the input feature, when it
              is set (and the FID column name is not the empty string), as the
              key to update existing features. It is crucial to make sure that
              the FID in the source and target layers are consistent.

              For the GPKG driver, it is also possible to upsert features
              whose FID is unset or non-significant (the --unset-fid option of
              gdal vector edit can be used to ignore the FID from the source
              feature), when there is a UNIQUE column that is not the integer
              primary key.

RETURN STATUS CODE
       The program returns status code 0 in case of success, and non-zero in
       case of error (non-blocking errors emitted as warnings are considered
       as a successful execution).

EXAMPLES
   Example 1: Compute a buffer of one km around input geometries (assuming the
       CRS is in meters)

          $ gdal vector buffer --distance=1000 in.gpkg out.gpkg --overwrite

   Example 2: Buffer a point dataset with 20 segments per quadrant (instead of
       default 8) to better approximate a circle

          $ gdal vector buffer --distance=20 --quadrant-segments=20 points.gpkg point_buffers.gpkg

   Example 3: Buffer lines to the left using join and end cap styles

          $ gdal vector buffer --distance=10 --endcap-style=flat --side=left --join-style=mitre --mitre-limit=2 lines.gpkg lines-buffer-endcap.gpkg

   Example 4: Clip and buffer a zipped line dataset as part of a pipeline
       Bash

          gdal vector pipeline \
          ! read "/vsizip/lines.zip" \
          ! clip --bbox 647903,6863599,648703,6864399 \
          ! buffer --distance=5 \
          ! write line-buffer.gpkg --overwrite
       PowerShell

          gdal vector pipeline `
          ! read "/vsizip/lines.zip" `
          ! clip --bbox 647903,6863599,648703,6864399 `
          ! buffer --distance=5 `
          ! write line-buffer.gpkg --overwrite

AUTHOR
       Even Rouault <even.rouault@spatialys.com>

COPYRIGHT
       1998-2026

                                August 18, 2026          GDAL-VECTOR-BUFFER(1)