mapshaper

mapshaper

Settings

ConsoleBasemapSimplifyExport

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Layers

No data has been added

Source files

Add files

Add empty layer

Select

Clip

Erase

Rectangle

Frame

Bounds

Cancel

Delete

Keep

Duplicate

Split

Bounds

Edit data

Clear

Export options

Layers

File format

Enter options from the command line interface for the -o command. Examples: bbox no-quantization precision=0.001. Click to see all options.

choose output directory

save to clipboard

Export

Basemap options

Clear

Fade

Simplification

prevent shape removal

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Prevent small polygon features from disappearing at high simplification. Keeps the largest ring of multi-ring features.

use planar geometry

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Treat x, y values as Cartesian coordinates on a plane, rather than as longitude, latitude coordinates on a sphere.

Method

Douglas-Peucker

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Simplified lines remain within a set distance of original lines. Good for thinning dense points, but spikes tend to form at high simplification.

Visvalingam / effective area

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Lines are simplified by iteratively removing the point that forms the least-area triangle with two adjacent points.

Visvalingam / weighted area

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Points located at the vertex of more acute angles are preferentially removed, for a smoother appearance.

Apply

Import files

with advanced options

Drop, paste or select files to import.

Shapefile, GeoJSON, TopoJSON, KML and CSV formats are supported. Files can be zipped or gzipped.

Enter options from the command line interface. Examples: snap no-topology encoding=big5. Click to see all options.

Submit

Check line intersections0 line intersections

Repair