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

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

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

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

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

Detect line intersections, including self-intersections, to help identify topological errors in a dataset.

Fix topology errors by snapping together points with nearly identical coordinates. This option does not apply to TopoJSON files.

Enter options from the command line interface. Examples: "no-topology" "encoding=big5"