Development Seed partnered with Wikimedia Italia to improve OSMCha, one of the most valuable OpenStreetMap validation tools.

Since its inception, OSMCha has become a core tool in the OpenStreetMap ecosystem. It keeps track of all changesets and makes them searchable by a large range of parameters, like date, location, users, etc. and provides some quality flags to the changesets, giving insights to users about possible data integrity problems. OSMCha updates minutely, making it the most sought after validation tool for OpenStreetMap.

Some of our team members at Development Seed are the people behind the creation and evolution of OSMCha, after it was first adopted by Mapbox in 2015. Nowadays, most companies that rely on OpenStreetMap data for their business use OSMCha in their data validation process.

One of the most wished capabilities for years has been the possibility to find changesets that affect a certain type of feature. For example, a user would like to know all the changesets that created, changed or deleted restaurants in New York or a company could be interested in monitoring changes to the railway network in India.

Wikimedia Italia provided funding for the development of this feature, and today we are releasing it to be used by the global OpenStreetMap community.

This feature could increase the complexity and size of the OSMCha database as it currently doesn't individual OSM features. It would be expensive to have the entire history of features in a database. Our team built a simple and efficient solution: store all the tags affected by a changeset. For example, a user changes a road from highway=primary to highway=secondary, and it's name from 1st Avenue to 2nd Avenue.

We register in the changeset database entry with that information and make it searchable. This way we are only storing what changed for each feature and can process this for every feature that is available in the minutely replication.

Have a look at this little video that searches changesets that modified cafés in London. Thank you Wikimedia Italia, for the partnership and for contributing to the success of OpenStreetMap! We encourage you to take a look at this addition to OSMCha and provide feedback.

Our team will be at State of the Map conference in Firenze, Italy and share our most recent and exciting projects to help grow OpenStreetMap. See you there!