Compare software

OpenCPN vs OpenSeaMap: catalog facts
OpenCPN	OpenSeaMap
Screenshots	Screenshots
Best for: Sailors who want a full chartplotter on a laptop or onboard computer	Best for: Sailors and paddlers who want free, community-maintained nautical charts
Free Free and open source.	Free Free to use and download.
Windows, macOS, Linux, Android	Web
Runs on Windows, macOS, Linux, Raspberry Pi and Android Plugin manager with a catalog of community plugins Designed for use at the helm while underway No cost for the software itself	Free charts built on OpenStreetMap Downloads for OpenCPN, Garmin and Lowrance Anyone can add and correct seamarks
Desktop-style interface is less suited to phones than dedicated mobile apps Some chart sets must be obtained separately	Community data is not an official chart Coverage and depth detail vary by region Some downloadable chart bundles are several years old
Downloadable app	Web application
Open source	Not open source
License not stated	License not stated
No account needed	No account needed
Offline features available	Not stated if it works offline
Official website Full listing and sources Sources for OpenCPN opencpn.org play.google.com/store/apps/details Catalog checked September 23, 2026	Official website Full listing and sources Sources for OpenSeaMap openseamap.org Catalog checked September 23, 2026

“Not stated” means we have not confirmed it. Features can vary by device and plan.

Screenshots