Downloading a "portable" version of Microsoft Visio is a common request, but it is important to know that Microsoft does not offer an official portable version of the desktop software.
If you need diagramming without installation, these are safe, portable, and often free: portable download microsoft visio portable
Progressive Web App (PWA): Using Microsoft Edge or Chrome, you can "Install this site as an app" from the Visio web portal. This gives you a desktop-like shortcut that doesn't require a full traditional installation. Downloading a "portable" version of Microsoft Visio is
No Installation Required: You can run it directly from external storage. these are safe