Your canvas is local by default.
MapMedium is designed so that diagram content can remain in your browser. This page explains where documents live, what can remove them, and how to keep durable backups.
What MapMedium stores
The application stores documents, document metadata, preferences, and recovery information in the browser’s site storage, primarily IndexedDB. If IndexedDB is unavailable, a limited localStorage fallback may be used.
- Documents are associated with this browser profile and the exact MapMedium web origin.
- No MapMedium account or cross-device sync is included.
- The service worker caches application files so the editor can reopen offline after a successful online load.
What can delete local documents
Use Export → MapMedium file for individual editable files and Download all backups on the home page for a browser-wide backup. Keep important files in a folder or backup system you control.
Network behaviour
The distributed build has no analytics library, advertising SDK, account service, remote font, or application API. The Content Security Policy limits network connections to the same origin. Static hosting providers may still receive ordinary web-server information such as IP address, request time, and requested path according to that provider’s own logs and policies.
Imported images are embedded as data inside the document when possible. Links placed in diagrams are opened only when the user activates them.
Permissions
MapMedium may ask the browser to grant persistent storage. The browser decides whether to grant it. Installation as a PWA and clipboard image access are also browser-controlled and may require a user action.
Before deploying your own copy
The site owner should update this page with their legal identity, contact details, host/CDN logging policy, jurisdiction-specific notices, and any optional services they add. Adding analytics, cloud storage, collaboration, authentication, or AI APIs changes the privacy model described here.