CoMaps, an offline mapping app built on OpenStreetMap data, helped rescue teams navigate the hardest‑hit areas of Venezuela after an earthquake on June 28, 2026. CoMaps is an open‑source application that stores regional maps on a phone and works without internet or cellular service, relying only on GPS. It was initially limited because map updates required days of server processing and app store approval. In April, the founders presented technical improvements to Humanitarian OpenStreetMap’s Geospatial Tech Working Group, enabling map sharing from a local device and reducing processing time from 10 days to about three days. These changes allowed weekly global map updates.

During the response, volunteers mapped affected locations through HOT’s Tasking Manager, and the resulting data was incorporated into CoMaps. Anton Wenemoser said the app let him locate destinations quickly when his team received instructions to move from one point to another. He noted that a team member was using a more limited navigation tool that did not include detailed volunteer‑generated features. Showing CoMaps to the team coordinator was described by Anton as a discovery he loved.

Céline Jacquin, HOT’s Latin America senior manager, said the app’s regular map updates help emergency actors who lack technical expertise to coordinate logistics. Emilio Mariscal, software engineering manager at HOT, thanked Bastian Greshake Tzovaras for rapid answers to questions about map availability. Bastian explained that the timing of the earthquake coincided with work already underway to make maps more accessible. He added that the thousands of buildings contributed through HOT’s Tasking Manager were already visible on the app for responders.

The CoMaps team aims to provide region‑specific updates every 12 hours, reducing the lag between mapping activity and on‑the‑ground availability. The project continues as a volunteer effort focused on humanitarian use rather than commercial gain. In the next emergency, users worldwide are likely to rely on the same offline map to guide rescue operations, illustrating how volunteer‑generated data can bridge humanitarian response and open geographic information.