OpenStreetMap US

OpenStreetMap US is excited to announce our latest Charter Project - OSMCha!

OSMCha is an open-source software project started in 2015 focusing on reporting, inspecting, and validating changes to OpenStreetMap. Its mission is to help the OpenStreetMap community to improve the quality of the map thereby increasing trust in the data for wider adoption.

The Charter Project designation provides OSMCha with a sustainable home that allows the project to be governed by input and leadership from across the community, including corporate users and donors. OSMCha is currently maintained by just a few developers, and becoming a charter project will bring more voices into developing a project roadmap which is vital to the long-term success and utility of OSMCha. The OSMCha Advisory Board saw the OpenStreetMap US Charter Project as a great opportunity and perhaps the only one that would provide this path.

At the core, OSMCha is a powerful API that queries OSM changesets based on tags, flags, and other metadata. The API allows users or external services to ‘flag’ certain changesets based on rules they determine. Users can see what changes have been made in a changeset and identify problems. Through encouraging manual flagging of changesets, OSMCha also serves as the largest corpus of open data for researchers, and folks working on better data validation tools, with manually reviewed and flagged OSM changeset data. This dataset has the potential to greatly benefit all future data validation efforts in OpenStreetMap.

From the OSMCha Advisory Board:

“We hope that as an OSM US Charter project, we can also grow to be a point of coordination for better tooling and to advocate for more cooperation around the data validation in OSM. We believe the OSM community is in the best position to handle data validation. To do this, we need well-designed, stable tools. We are grateful that OSMCha has grown to become one of the only OSM tools that allows the community to manually validate data via a user-friendly interface.

In the longer term, we hope that a home with OSM US allows us to more broadly approach the data validation problem in OSM. There is a lot we can do, and being an OSM US Charter project will allow us to engage the  community on structuring how OSMCha can fit into larger efforts around better data quality in OSM.”

OpenStreetMap US is thrilled to support OSMCha’s growth and sustainability. We will continue to share updates from OSMCha and more ways to become involved in the near future. Learn more information on the OpenStreetMap US Charter Projects Program here.

Get involved

Interested in joining the conversation and supporting OSMCha? Join the #osmcha channel on the OSMUS slack.

More info


What are people mapping? OSMCha is an advanced (yet easy-to-use) tool to analyze bundles of OpenStreetMap edits, called changesets. Advanced filters, vandalism detection, and on-map visualization help you find and verify the changesets you care about.

Charter Projects

Our Charter Project program provides a long-term home for notable OpenStreetMap tools, programs, and services. We provide projects with a stable legal and fiscal framework, so developers and organizers can focus on what they do best: building things.