Mapshaper is software for editing Shapefile, GeoJSON, TopoJSON and several other data formats, written in JavaScript.

The mapshaper command line program supports common map making tasks like simplifying shapes, editing attribute data, clipping, erasing, dissolving, filtering and more.

There is a web-based gui for interactive simplification.

See the project wiki for documentation on using mapshaper.

To suggest improvements, add an issue.

To catch up on the latest changes, read the changelog.

The mapshaper command line program has been used successfully under Mac OS X, Linux and Windows.

The project wiki has an introduction to using the command line tool that includes many simple examples.

For a detailed reference, see the Command Reference.

The interactive web interface works in recent versions of Chrome and Firefox as well as IE 10+. Exporting is not supported in Safari. If you encounter out-of-memory errors using Chrome, try Firefox, which can handle Shapefiles larger than 1GB.

The mapshaper distribution includes the script mapshaper-gui, which runs mapshaper's web interface locally. You can also visit mapshaper.org to use mapshaper online.

All processing is done in the browser, so your data stays private, even when using the public website.

Mapshaper requires Node.js. There are easy installers for Microsoft Windows and other platforms.

With Node installed, you can install the latest release version using npm. Install with the "-g" flag to make the executable scripts available systemwide.

npm install -g mapshaper

To install and run the latest development code from github:

git clone [email protected]:mbloch/mapshaper.git
cd mapshaper
npm install
bin/mapshaper-gui # use the web interface locally
bin/mapshaper     # use the command line tool

Run the build script after editing any of the files in the src/ or lib/ directories.

Run npm test in the project directory to run mapshaper's tests.

This software is licensed under MPL 2.0.

According to Mozilla's FAQ, "The MPL's ‘file-level’ copyleft is designed to encourage contributors to share modifications they make to your code, while still allowing them to combine your code with code under other licenses (open or proprietary) with minimal restrictions."

Mike Bostock, for developing the TopoJSON format and for all-around helpfulness.

Shan Carter, for help designing mapshaper's web interface.

Mark Harrower, for collaborating on the original MapShaper program at the University of Wisconsin–Madison.